Automation Testing Interview Questions & Answers (2026)

Headless mode or screen resolution, timing issues, environment data, missing dependencies, browser–driver version mismatch or parallel conflicts. Check logs and failure screenshots and make waits robust.

POST creates a resource, PUT replaces the whole resource (idempotent) and PATCH updates part of it.

Keep credentials in external data, parameterise the test with a data provider, reuse a login method in a page class, and clear sessions between roles.

Use then().statusCode(200).body("data.id", equalTo(5)), or extract() the response and assert fields with JsonPath.

A callback where one system sends an HTTP request to another when an event occurs. Test with a mock receiver or tools such as webhook.site and verify the payload.

A try block that automatically closes resources such as file readers or streams, preventing leaks without a finally block.

ArrayList stores an ordered list (e.g. all product names on a page). HashMap stores key–value pairs (e.g. test data or config properties).

id, name, className, tagName, linkText, partialLinkText, CSS selector and XPath. Prefer stable ids or CSS, using XPath when needed.

BeforeSuite, BeforeTest, BeforeClass, BeforeMethod, Test, AfterMethod, AfterClass, AfterTest and AfterSuite.

Set window size explicitly, use proper waits, check animations and viewport differences, and capture screenshots and logs to find timing issues.

An interface for systems to talk to each other. GET reads, POST creates, PUT replaces, PATCH updates partially and DELETE removes.

Runtime events that disrupt flow. Use try-catch-finally, throw, throws, and custom exceptions; checked exceptions must be handled while unchecked ones need not be.

Implicit, explicit (WebDriverWait with ExpectedConditions) and fluent waits; avoid mixing implicit and explicit waits and never rely on Thread.sleep.

Use TestNG parallel="methods | classes | tests" with thread-count, keep WebDriver in a ThreadLocal, and use Selenium Grid or a cloud grid for multiple browsers.

A subclass redefines a parent method. Frameworks use it to customise base behaviour, such as overriding a wait or click method in a base page class.

Use isDisplayed(), isEnabled() and isSelected() on the WebElement before interacting or asserting.

Use mocks or stubs such as WireMock to simulate the dependency and test your service in isolation.

Docker packages tools in containers so tests run identically everywhere; Selenium Grid and browsers can be started quickly in containers.

String is immutable — every change creates a new object. StringBuilder is mutable and faster for repeated changes (not thread-safe; StringBuffer is).

//button[normalize-space()='Login'] //button[contains(text(),'Login')]

A helper that initialises @FindBy elements lazily using initElements; some teams skip it in favour of plain By locators.

Implement ITestListener.onTestFailure(): File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE); then copy it into the reports folder.

Code pushed to Git → Jenkins job triggers (webhook or schedule) → mvn clean test with the suite XML → reports and screenshots published → notifications on Slack/email → failures triaged before release.

A special method that initialises an object. It can be overloaded with different parameters, and testers use it to pass the WebDriver into page classes.

Use then().time(lessThan(2000L)) and then().header("Content-Type", containsString("json")) along with body assertions.

final makes a variable, method or class unchangeable; finally is a block that always runs after try-catch; finalize is a deprecated method called before garbage collection.

A design pattern where each page is a class holding its locators and actions, so tests stay readable and a locator change is fixed in one place.

Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

Keep credentials in external data, parameterise the test with a data provider, reuse a login method in a page class, and clear sessions between roles.

Schedule the job, spin up environments or containers, run suites in parallel, store reports and screenshots, notify failures on Slack or email and track trends.

Click to open the dropdown, then locate the option by its text, e.g. //li[text()='India'], and click it. Add an explicit wait for the animation.

An authorisation framework where a client obtains an access token from an auth server and sends it as a Bearer token; tests fetch and reuse the token in setup.

Continuous Integration builds and tests every commit, and Continuous Delivery ships automatically. Automated tests give fast feedback and gate releases.

Classes such as Integer and Double that wrap primitive types as objects, needed for collections and for parsing text from web elements.

this refers to the current object; super refers to the parent class, used to call parent constructors and methods.

Do not automate it; ask for a test environment where CAPTCHA is disabled or use test keys, or a bypass token agreed with developers.

Arrays have a fixed size and can hold primitives; ArrayList grows dynamically, holds objects and offers helper methods.

Overloading: same method name, different parameters, in the same class (compile time). Overriding: a subclass redefines a parent method with the same signature (runtime polymorphism). WebDriver driver = new ChromeDriver() is runtime polymorphism.

Maven project → POM with a BasePage → driver factory with ThreadLocal → config files → data-driven utilities (Excel/JSON) → TestNG or Cucumber runner → logging → Extent reports with screenshots on failure → Jenkins pipeline.

Git tracks changes, enables code review, branching and rollback and lets teams collaborate on the framework safely.

Keep URLs and credentials in per-environment config files or variables, choose with a command-line parameter and never hard-code secrets.

It uses the key's hashCode to find a bucket and equals to resolve collisions, giving O(1) average lookups; Java 8 converts long buckets into trees.

A helper that initialises @FindBy elements lazily using initElements; some teams skip it in favour of plain By locators.

//button[normalize-space()='Login'] //button[contains(text(),'Login')]

Automate stable, repetitive, high-risk and data-heavy flows (smoke, regression). Skip one-time tests, frequently changing UI and checks needing human judgement. Compare run frequency × manual time with build and maintenance cost.

Runtime events that disrupt flow. Use try-catch-finally, throw, throws, and custom exceptions; checked exceptions must be handled while unchecked ones need not be.

Implicit wait applies globally to element lookups. Explicit wait waits for a specific condition (WebDriverWait + ExpectedConditions). Fluent wait is an explicit wait with custom polling and ignored exceptions.

Define parameter name and value in the XML and read them with @Parameters in the test or configuration method.

Running the same test logic with multiple data sets from Excel, CSV, JSON or a database, so coverage increases without duplicating code.

Code pushed to Git → Jenkins job triggers (webhook or schedule) → mvn clean test with the suite XML → reports and screenshots published → notifications on Slack/email → failures triaged before release.

BeforeSuite, BeforeTest, BeforeClass, BeforeMethod, Test, AfterMethod, AfterClass, AfterTest and AfterSuite.

Use then().statusCode(200).body("data.id", equalTo(5)), or extract() the response and assert fields with JsonPath.

Use mocks or stubs such as WireMock to simulate the dependency and test your service in isolation.

== compares references (or primitive values); equals() compares content when overridden, as in String.

Comparable defines the natural order inside the class (compareTo); Comparator defines custom orders externally (compare), useful for sorting test data in several ways.

Keep credentials in external data, parameterise the test with a data provider, reuse a login method in a page class, and clear sessions between roles.

An abstract class can hold state and concrete methods; an interface defines a contract (with default methods since Java 8). A class extends one abstract class but can implement many interfaces.

Implicit, explicit (WebDriverWait with ExpectedConditions) and fluent waits; avoid mixing implicit and explicit waits and never rely on Thread.sleep.

WebDriver sends commands over HTTP (W3C protocol) to a browser-specific driver such as chromedriver, which controls the actual browser.

Use Apache POI for Excel and the Properties class for config files, loaded in a utility class so tests read data instead of hard-coding it.

It manages dependencies through pom.xml, builds the project, runs tests with Surefire and standardises structure across teams.

findElement returns the first match and throws NoSuchElementException if nothing is found. findElements returns a List (empty if nothing is found) — handy to check whether an element exists.

close() closes the current window; quit() closes all windows and ends the driver session.

Continuous Integration builds and tests every commit, and Continuous Delivery ships automatically. Automated tests give fast feedback and gate releases.

An open-source suite for browser automation: WebDriver, IDE, Grid and the older RC. WebDriver controls browsers through their native drivers.

It runs tests in parallel across multiple machines and browsers using a hub and nodes, cutting execution time and increasing browser coverage.

Stabilise waits and data, isolate tests, use retries cautiously, quarantine unstable tests, run in consistent containers and track flaky rates.

Encapsulation, inheritance, polymorphism and abstraction. Testers use them to build reusable page classes, base tests and utility libraries.

Locators such as above, below, toLeftOf and near that find elements by their position relative to another element.

Tag tests with groups = {"smoke","regression"} and include or exclude them in testng.xml to run chosen sets.

String is immutable — every change creates a new object. StringBuilder is mutable and faster for repeated changes (not thread-safe; StringBuffer is).

If the element is <input type="file">, use element.sendKeys("C:/path/file.pdf"). Use the Robot class or AutoIt only as a last resort for OS dialogs.

A Java library that makes API tests readable using given-when-then, with easy request building, response validation and JSON path support.

It uses the key's hashCode to find a bucket and equals to resolve collisions, giving O(1) average lookups; Java 8 converts long buckets into trees.

Verifying that a provider and consumer agree on request and response formats, using tools like Pact, to catch breaking changes early.

Implement IRetryAnalyzer with a retry count and attach it through the test annotation or a listener to rerun flaky tests.

A framework combining data-driven, keyword-driven and POM approaches with reporting and utilities, giving flexibility and reuse.

throw actually raises an exception object inside a method; throws declares in the method signature that it may pass an exception to the caller.

Cast the driver to JavascriptExecutor and use executeScript, for example to scroll into view or click hidden elements.

Mouse and keyboard actions such as hover, drag and drop, double click, right click and key combinations, built with moveToElement(...).perform().

Lambdas are short anonymous functions; streams process collections declaratively with filter, map and collect, for example filtering link text from a list of elements.

ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

Relative locators, improved Grid, W3C compliance, new window or tab creation, Chrome DevTools Protocol access and element-level screenshots.

Encapsulation: private locators with public page methods. Inheritance: pages extend a BasePage. Polymorphism: the WebDriver interface for different browsers. Abstraction: utility layers hiding Selenium details.

id, name, className, tagName, linkText, partialLinkText, CSS selector and XPath. Prefer stable ids or CSS, using XPath when needed.

Keep URLs and credentials in per-environment config files or variables, choose with a command-line parameter and never hard-code secrets.

Use isDisplayed(), isEnabled() and isSelected() on the WebElement before interacting or asserting.

switchTo().frame(index, name or element) enters the frame, and switchTo().defaultContent() returns to the main page.

Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

Use JavascriptExecutor with window.scrollTo or scrollIntoView, or the Actions class scroll methods in Selenium 4.

It makes a test run only after specified tests pass, otherwise it is skipped. Use sparingly as it creates coupled tests.

Locate rows and columns with XPath such as //table//tr and //td, loop through them to read or click cells, or build the XPath dynamically from the row text.

given().baseUri(url) .when().get("/users/1") .then().statusCode(200).body("id", equalTo(1));

One interface, many forms. WebDriver driver = new ChromeDriver() lets the same test code run on any browser class that implements WebDriver.

this refers to the current object; super refers to the parent class, used to call parent constructors and methods.

final makes a variable, method or class unchangeable; finally is a block that always runs after try-catch; finalize is a deprecated method called before garbage collection.

Compare effort saved by running automated tests repeatedly against the cost of building and maintaining scripts, counting execution time, defects found earlier and release speed.

@BeforeTest runs once before all methods in a test tag of testng.xml; @BeforeMethod runs before every test method.

Absolute starts from the root (/html/...) and breaks easily; relative starts anywhere with // and is more stable, for example //input[@id='email'].

Create a job or pipeline that checks out code, runs mvn test, publishes reports and triggers on commits or schedules.

200 OK, 201 Created, 204 No Content, 400 Bad Request, 401 Unauthorized, 403 Forbidden, 404 Not Found, 500 Internal Server Error.

ArrayList stores an ordered list (e.g. all product names on a page). HashMap stores key–value pairs (e.g. test data or config properties).

Use then().time(lessThan(2000L)) and then().header("Content-Type", containsString("json")) along with body assertions.

An authorisation framework where a client obtains an access token from an auth server and sends it as a Bearer token; tests fetch and reuse the token in setup.

A scripted or declarative Jenkinsfile that defines stages such as build, test and deploy as code stored with the project.

A design pattern where each page is a class holding its locators and actions, so tests stay readable and a locator change is fixed in one place.

Schedule the job, spin up environments or containers, run suites in parallel, store reports and screenshots, notify failures on Slack or email and track trends.

Static members belong to the class and are shared by all instances; non-static members belong to each object.

Headless mode or screen resolution, timing issues, environment data, missing dependencies, browser–driver version mismatch or parallel conflicts. Check logs and failure screenshots and make waits robust.

A method annotated with @DataProvider returns a 2D object array and the test with dataProvider = "name" runs once per row.

Get getWindowHandles(), loop to find the target, and call driver.switchTo().window(handle); switch back using the stored parent handle.

throw actually raises an exception object inside a method; throws declares in the method signature that it may pass an exception to the caller.

Compare effort saved by running automated tests repeatedly against the cost of building and maintaining scripts, counting execution time, defects found earlier and release speed.

Behaviour-driven development writes scenarios in Given-When-Then Gherkin that map to step definitions in code, so business and QA share one language.

this refers to the current object; super refers to the parent class, used to call parent constructors and methods.

Implement ITestListener.onTestFailure(): File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE); then copy it into the reports folder.

Implicit wait applies globally to element lookups. Explicit wait waits for a specific condition (WebDriverWait + ExpectedConditions). Fluent wait is an explicit wait with custom polling and ignored exceptions.

A configuration file to define suites, tests, classes, groups, parameters and parallel execution settings.

A framework combining data-driven, keyword-driven and POM approaches with reporting and utilities, giving flexibility and reuse.

Encapsulation: private locators with public page methods. Inheritance: pages extend a BasePage. Polymorphism: the WebDriver interface for different browsers. Abstraction: utility layers hiding Selenium details.

Continuous Integration builds and tests every commit, and Continuous Delivery ships automatically. Automated tests give fast feedback and gate releases.

A callback where one system sends an HTTP request to another when an event occurs. Test with a mock receiver or tools such as webhook.site and verify the payload.

given().baseUri(url) .when().get("/users/1") .then().statusCode(200).body("id", equalTo(1));

One interface, many forms. WebDriver driver = new ChromeDriver() lets the same test code run on any browser class that implements WebDriver.

Use external files or APIs and database setup scripts, generate unique data per run, and clean up afterwards so tests stay independent.

Use then().statusCode(200).body("data.id", equalTo(5)), or extract() the response and assert fields with JsonPath.

A test framework offering annotations, grouping, prioritisation, parallel runs, data providers and reports, which structure and scale Selenium tests.

WebDriver sends commands over HTTP (W3C protocol) to a browser-specific driver such as chromedriver, which controls the actual browser.

Maven project → POM with a BasePage → driver factory with ThreadLocal → config files → data-driven utilities (Excel/JSON) → TestNG or Cucumber runner → logging → Extent reports with screenshots on failure → Jenkins pipeline.

ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

A try block that automatically closes resources such as file readers or streams, preventing leaks without a finally block.

switchTo().frame(index, name or element) enters the frame, and switchTo().defaultContent() returns to the main page.

A Java library that makes API tests readable using given-when-then, with easy request building, response validation and JSON path support.

Running the same test logic with multiple data sets from Excel, CSV, JSON or a database, so coverage increases without duplicating code.

Use mocks or stubs such as WireMock to simulate the dependency and test your service in isolation.

findElement returns the first match and throws NoSuchElementException if nothing is found. findElements returns a List (empty if nothing is found) — handy to check whether an element exists.

Keep URLs and credentials in per-environment config files or variables, choose with a command-line parameter and never hard-code secrets.

public (everywhere), protected (package and subclasses), default (package) and private (same class), used to control visibility of test utilities.

Stabilise waits and data, isolate tests, use retries cautiously, quarantine unstable tests, run in consistent containers and track flaky rates.

SOAP is a strict XML protocol with WSDL and WS-Security; REST is a lighter architectural style using HTTP and usually JSON.

Headless mode or screen resolution, timing issues, environment data, missing dependencies, browser–driver version mismatch or parallel conflicts. Check logs and failure screenshots and make waits robust.

Implement IRetryAnalyzer with a retry count and attach it through the test annotation or a listener to rerun flaky tests.

Code pushed to Git → Jenkins job triggers (webhook or schedule) → mvn clean test with the suite XML → reports and screenshots published → notifications on Slack/email → failures triaged before release.

It uses the key's hashCode to find a bucket and equals to resolve collisions, giving O(1) average lookups; Java 8 converts long buckets into trees.

It manages dependencies through pom.xml, builds the project, runs tests with Surefire and standardises structure across teams.

A lightweight text format of key-value pairs and arrays used in API requests and responses, validated field by field in tests.

Define parameter name and value in the XML and read them with @Parameters in the test or configuration method.

Overloading: same method name, different parameters, in the same class (compile time). Overriding: a subclass redefines a parent method with the same signature (runtime polymorphism). WebDriver driver = new ChromeDriver() is runtime polymorphism.

Classes such as Integer and Double that wrap primitive types as objects, needed for collections and for parsing text from web elements.

Arrays have a fixed size and can hold primitives; ArrayList grows dynamically, holds objects and offers helper methods.

getText returns visible inner text; getAttribute returns an HTML attribute or property such as value, href or class.

Implicit, explicit (WebDriverWait with ExpectedConditions) and fluent waits; avoid mixing implicit and explicit waits and never rely on Thread.sleep.

Classes such as Integer and Double that wrap primitive types as objects, needed for collections and for parsing text from web elements.

Use Apache POI for Excel and the Properties class for config files, loaded in a utility class so tests read data instead of hard-coding it.

Comparable defines the natural order inside the class (compareTo); Comparator defines custom orders externally (compare), useful for sorting test data in several ways.

Stabilise waits and data, isolate tests, use retries cautiously, quarantine unstable tests, run in consistent containers and track flaky rates.

An abstract class can hold state and concrete methods; an interface defines a contract (with default methods since Java 8). A class extends one abstract class but can implement many interfaces.

Automate stable, repetitive, high-risk and data-heavy flows (smoke, regression). Skip one-time tests, frequently changing UI and checks needing human judgement. Compare run frequency × manual time with build and maintenance cost.

Create a job or pipeline that checks out code, runs mvn test, publishes reports and triggers on commits or schedules.

Implement ITestListener.onTestFailure(): File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE); then copy it into the reports folder.

It manages dependencies through pom.xml, builds the project, runs tests with Surefire and standardises structure across teams.

An open-source suite for browser automation: WebDriver, IDE, Grid and the older RC. WebDriver controls browsers through their native drivers.

driver.switchTo().alert() lets you accept, dismiss, read text or send keys. Browser windows are handled with window handles.

Behaviour-driven development writes scenarios in Given-When-Then Gherkin that map to step definitions in code, so business and QA share one language.

A framework combining data-driven, keyword-driven and POM approaches with reporting and utilities, giving flexibility and reuse.

switchTo().frame(index, name or element) enters the frame, and switchTo().defaultContent() returns to the main page.

Store each driver in a ThreadLocal so every thread gets its own instance and tests do not interfere.

A configuration file to define suites, tests, classes, groups, parameters and parallel execution settings.

Cast the driver to JavascriptExecutor and use executeScript, for example to scroll into view or click hidden elements.

A callback where one system sends an HTTP request to another when an event occurs. Test with a mock receiver or tools such as webhook.site and verify the payload.

Maven project → POM with a BasePage → driver factory with ThreadLocal → config files → data-driven utilities (Excel/JSON) → TestNG or Cucumber runner → logging → Extent reports with screenshots on failure → Jenkins pipeline.

An open-source suite for browser automation: WebDriver, IDE, Grid and the older RC. WebDriver controls browsers through their native drivers.

It manages dependencies through pom.xml, builds the project, runs tests with Surefire and standardises structure across teams.

An authorisation framework where a client obtains an access token from an auth server and sends it as a Bearer token; tests fetch and reuse the token in setup.

Click to open the dropdown, then locate the option by its text, e.g. //li[text()='India'], and click it. Add an explicit wait for the animation.

Code pushed to Git → Jenkins job triggers (webhook or schedule) → mvn clean test with the suite XML → reports and screenshots published → notifications on Slack/email → failures triaged before release.

Define parameter name and value in the XML and read them with @Parameters in the test or configuration method.

Use isDisplayed(), isEnabled() and isSelected() on the WebElement before interacting or asserting.

id, name, className, tagName, linkText, partialLinkText, CSS selector and XPath. Prefer stable ids or CSS, using XPath when needed.

Runtime events that disrupt flow. Use try-catch-finally, throw, throws, and custom exceptions; checked exceptions must be handled while unchecked ones need not be.

Use CSS or XPath with contains(), starts-with() or stable attributes, relative axes, or data-test attributes agreed with developers.

Create a job or pipeline that checks out code, runs mvn test, publishes reports and triggers on commits or schedules.

BeforeSuite, BeforeTest, BeforeClass, BeforeMethod, Test, AfterMethod, AfterClass, AfterTest and AfterSuite.

Get getWindowHandles(), loop to find the target, and call driver.switchTo().window(handle); switch back using the stored parent handle.

Use then().time(lessThan(2000L)) and then().header("Content-Type", containsString("json")) along with body assertions.

Mouse and keyboard actions such as hover, drag and drop, double click, right click and key combinations, built with moveToElement(...).perform().

ArrayList stores an ordered list (e.g. all product names on a page). HashMap stores key–value pairs (e.g. test data or config properties).

//button[normalize-space()='Login'] //button[contains(text(),'Login')]

A subclass redefines a parent method. Frameworks use it to customise base behaviour, such as overriding a wait or click method in a base page class.

Use headers such as Bearer tokens, basic auth, API keys or OAuth flows; fetch a token in a setup step and reuse it.

A framework combining data-driven, keyword-driven and POM approaches with reporting and utilities, giving flexibility and reuse.

Locate rows and columns with XPath such as //table//tr and //td, loop through them to read or click cells, or build the XPath dynamically from the row text.

findElement returns the first match and throws NoSuchElementException if nothing is found. findElements returns a List (empty if nothing is found) — handy to check whether an element exists.

Relative locators, improved Grid, W3C compliance, new window or tab creation, Chrome DevTools Protocol access and element-level screenshots.

A lightweight text format of key-value pairs and arrays used in API requests and responses, validated field by field in tests.

It runs tests in parallel across multiple machines and browsers using a hub and nodes, cutting execution time and increasing browser coverage.

It uses the key's hashCode to find a bucket and equals to resolve collisions, giving O(1) average lookups; Java 8 converts long buckets into trees.

Lambdas are short anonymous functions; streams process collections declaratively with filter, map and collect, for example filtering link text from a list of elements.

Use JavascriptExecutor with window.scrollTo or scrollIntoView, or the Actions class scroll methods in Selenium 4.

Set window size explicitly, use proper waits, check animations and viewport differences, and capture screenshots and logs to find timing issues.

Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

A configuration file to define suites, tests, classes, groups, parameters and parallel execution settings.

Use Apache POI for Excel and the Properties class for config files, loaded in a utility class so tests read data instead of hard-coding it.

An interface for systems to talk to each other. GET reads, POST creates, PUT replaces, PATCH updates partially and DELETE removes.

Keep credentials in external data, parameterise the test with a data provider, reuse a login method in a page class, and clear sessions between roles.

Implement ITestListener.onTestFailure(): File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE); then copy it into the reports folder.

this refers to the current object; super refers to the parent class, used to call parent constructors and methods.

A method annotated with @DataProvider returns a 2D object array and the test with dataProvider = "name" runs once per row.

String is immutable — every change creates a new object. StringBuilder is mutable and faster for repeated changes (not thread-safe; StringBuffer is).

Running the same test logic with multiple data sets from Excel, CSV, JSON or a database, so coverage increases without duplicating code.

Runtime events that disrupt flow. Use try-catch-finally, throw, throws, and custom exceptions; checked exceptions must be handled while unchecked ones need not be.

Use the Select class with selectByVisibleText, selectByValue or selectByIndex; for custom dropdowns click and choose from the list of elements.

Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

switchTo().frame(index, name or element) enters the frame, and switchTo().defaultContent() returns to the main page.

Store each driver in a ThreadLocal so every thread gets its own instance and tests do not interfere.

Use then().time(lessThan(2000L)) and then().header("Content-Type", containsString("json")) along with body assertions.

ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

findElement returns the first match and throws NoSuchElementException if nothing is found. findElements returns a List (empty if nothing is found) — handy to check whether an element exists.

A test framework offering annotations, grouping, prioritisation, parallel runs, data providers and reports, which structure and scale Selenium tests.

Classes like ITestListener that react to events such as test start, success or failure, commonly used for screenshots and reporting.

Docker packages tools in containers so tests run identically everywhere; Selenium Grid and browsers can be started quickly in containers.

given().baseUri(url) .when().get("/users/1") .then().statusCode(200).body("id", equalTo(1));

It runs tests in parallel across multiple machines and browsers using a hub and nodes, cutting execution time and increasing browser coverage.

A design pattern where each page is a class holding its locators and actions, so tests stay readable and a locator change is fixed in one place.

Static members belong to the class and are shared by all instances; non-static members belong to each object.

Implicit, explicit (WebDriverWait with ExpectedConditions) and fluent waits; avoid mixing implicit and explicit waits and never rely on Thread.sleep.

Tag tests with groups = {"smoke","regression"} and include or exclude them in testng.xml to run chosen sets.

It makes a test run only after specified tests pass, otherwise it is skipped. Use sparingly as it creates coupled tests.

A scripted or declarative Jenkinsfile that defines stages such as build, test and deploy as code stored with the project.

A method annotated with @DataProvider returns a 2D object array and the test with dataProvider = "name" runs once per row.

Encapsulation, inheritance, polymorphism and abstraction. Testers use them to build reusable page classes, base tests and utility libraries.

Keep credentials in external data, parameterise the test with a data provider, reuse a login method in a page class, and clear sessions between roles.

Runtime events that disrupt flow. Use try-catch-finally, throw, throws, and custom exceptions; checked exceptions must be handled while unchecked ones need not be.

200 OK, 201 Created, 400 bad request, 401 unauthenticated, 403 forbidden, 404 not found and 500 server error.

Use mocks or stubs such as WireMock to simulate the dependency and test your service in isolation.

Lambdas are short anonymous functions; streams process collections declaratively with filter, map and collect, for example filtering link text from a list of elements.

An authorisation framework where a client obtains an access token from an auth server and sends it as a Bearer token; tests fetch and reuse the token in setup.

getText returns visible inner text; getAttribute returns an HTML attribute or property such as value, href or class.

Behaviour-driven development writes scenarios in Given-When-Then Gherkin that map to step definitions in code, so business and QA share one language.

One interface, many forms. WebDriver driver = new ChromeDriver() lets the same test code run on any browser class that implements WebDriver.

String r = new StringBuilder(s).reverse().toString(); // or loop from the last index and append each character

Store each driver in a ThreadLocal so every thread gets its own instance and tests do not interfere.

ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

Use isDisplayed(), isEnabled() and isSelected() on the WebElement before interacting or asserting.

Git tracks changes, enables code review, branching and rollback and lets teams collaborate on the framework safely.

Create a job or pipeline that checks out code, runs mvn test, publishes reports and triggers on commits or schedules.

== compares references (or primitive values); equals() compares content when overridden, as in String.

Arrays have a fixed size and can hold primitives; ArrayList grows dynamically, holds objects and offers helper methods.

== compares references (or primitive values); equals() compares content when overridden, as in String.

Overloading: same method name, different parameters, in the same class (compile time). Overriding: a subclass redefines a parent method with the same signature (runtime polymorphism). WebDriver driver = new ChromeDriver() is runtime polymorphism.

An API client. Add tests in JavaScript, use environments and collections, and run them with Newman in a CI pipeline.

Use JavascriptExecutor with window.scrollTo or scrollIntoView, or the Actions class scroll methods in Selenium 4.

Git tracks changes, enables code review, branching and rollback and lets teams collaborate on the framework safely.

final makes a variable, method or class unchangeable; finally is a block that always runs after try-catch; finalize is a deprecated method called before garbage collection.

Verifying that a provider and consumer agree on request and response formats, using tools like Pact, to catch breaking changes early.

Get getWindowHandles(), loop to find the target, and call driver.switchTo().window(handle); switch back using the stored parent handle.

Locate rows and columns with XPath such as //table//tr and //td, loop through them to read or click cells, or build the XPath dynamically from the row text.

Relative locators, improved Grid, W3C compliance, new window or tab creation, Chrome DevTools Protocol access and element-level screenshots.

Implicit, explicit (WebDriverWait with ExpectedConditions) and fluent waits; avoid mixing implicit and explicit waits and never rely on Thread.sleep.

//button[normalize-space()='Login'] //button[contains(text(),'Login')]

Store each driver in a ThreadLocal so every thread gets its own instance and tests do not interfere.

Use mocks or stubs such as WireMock to simulate the dependency and test your service in isolation.

Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

Headless mode or screen resolution, timing issues, environment data, missing dependencies, browser–driver version mismatch or parallel conflicts. Check logs and failure screenshots and make waits robust.

this refers to the current object; super refers to the parent class, used to call parent constructors and methods.

Keep URLs and credentials in per-environment config files or variables, choose with a command-line parameter and never hard-code secrets.

Lambdas are short anonymous functions; streams process collections declaratively with filter, map and collect, for example filtering link text from a list of elements.

Cast the driver to JavascriptExecutor and use executeScript, for example to scroll into view or click hidden elements.

Encapsulation: private locators with public page methods. Inheritance: pages extend a BasePage. Polymorphism: the WebDriver interface for different browsers. Abstraction: utility layers hiding Selenium details.

Locators such as above, below, toLeftOf and near that find elements by their position relative to another element.

An authorisation framework where a client obtains an access token from an auth server and sends it as a Bearer token; tests fetch and reuse the token in setup.

ArrayList has fast random access and slower inserts in the middle; LinkedList has fast inserts and deletes but slow access by index.

Schedule the job, spin up environments or containers, run suites in parallel, store reports and screenshots, notify failures on Slack or email and track trends.

Hard assert stops the test at the first failure; SoftAssert collects failures and reports them together when assertAll() is called.

ArrayList stores an ordered list (e.g. all product names on a page). HashMap stores key–value pairs (e.g. test data or config properties).

A subclass redefines a parent method. Frameworks use it to customise base behaviour, such as overriding a wait or click method in a base page class.

Keep URLs and credentials in per-environment config files or variables, choose with a command-line parameter and never hard-code secrets.

getText returns visible inner text; getAttribute returns an HTML attribute or property such as value, href or class.

Comparable defines the natural order inside the class (compareTo); Comparator defines custom orders externally (compare), useful for sorting test data in several ways.

throw actually raises an exception object inside a method; throws declares in the method signature that it may pass an exception to the caller.

Behaviour-driven development writes scenarios in Given-When-Then Gherkin that map to step definitions in code, so business and QA share one language.

this refers to the current object; super refers to the parent class, used to call parent constructors and methods.

Verifying that a provider and consumer agree on request and response formats, using tools like Pact, to catch breaking changes early.

Use Apache POI for Excel and the Properties class for config files, loaded in a utility class so tests read data instead of hard-coding it.

ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

Use CSS or XPath with contains(), starts-with() or stable attributes, relative axes, or data-test attributes agreed with developers.

If the element is <input type="file">, use element.sendKeys("C:/path/file.pdf"). Use the Robot class or AutoIt only as a last resort for OS dialogs.

SOAP is a strict XML protocol with WSDL and WS-Security; REST is a lighter architectural style using HTTP and usually JSON.

A framework combining data-driven, keyword-driven and POM approaches with reporting and utilities, giving flexibility and reuse.

findElement returns the first match and throws NoSuchElementException if nothing is found. findElements returns a List (empty if nothing is found) — handy to check whether an element exists.

== compares references (or primitive values); equals() compares content when overridden, as in String.

Cast the driver to JavascriptExecutor and use executeScript, for example to scroll into view or click hidden elements.

Use headers such as Bearer tokens, basic auth, API keys or OAuth flows; fetch a token in a setup step and reuse it.

It manages dependencies through pom.xml, builds the project, runs tests with Surefire and standardises structure across teams.

Implement IRetryAnalyzer with a retry count and attach it through the test annotation or a listener to rerun flaky tests.

Implicit wait applies globally to element lookups. Explicit wait waits for a specific condition (WebDriverWait + ExpectedConditions). Fluent wait is an explicit wait with custom polling and ignored exceptions.

driver.switchTo().alert() lets you accept, dismiss, read text or send keys. Browser windows are handled with window handles.

Create a job or pipeline that checks out code, runs mvn test, publishes reports and triggers on commits or schedules.

Keep credentials in external data, parameterise the test with a data provider, reuse a login method in a page class, and clear sessions between roles.

Static members belong to the class and are shared by all instances; non-static members belong to each object.

Re-locate the element after the DOM refreshes, use explicit waits for the refreshed element, don't keep element references for long, or wrap the action in retry logic.

A callback where one system sends an HTTP request to another when an event occurs. Test with a mock receiver or tools such as webhook.site and verify the payload.

Get getWindowHandles(), loop to find the target, and call driver.switchTo().window(handle); switch back using the stored parent handle.

Use the Select class with selectByVisibleText, selectByValue or selectByIndex; for custom dropdowns click and choose from the list of elements.

Stabilise waits and data, isolate tests, use retries cautiously, quarantine unstable tests, run in consistent containers and track flaky rates.

Compare effort saved by running automated tests repeatedly against the cost of building and maintaining scripts, counting execution time, defects found earlier and release speed.

A method annotated with @DataProvider returns a 2D object array and the test with dataProvider = "name" runs once per row.

Implement ITestListener.onTestFailure(): File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE); then copy it into the reports folder.

Use external files or APIs and database setup scripts, generate unique data per run, and clean up afterwards so tests stay independent.

A scripted or declarative Jenkinsfile that defines stages such as build, test and deploy as code stored with the project.

close() closes the current window; quit() closes all windows and ends the driver session.

Docker packages tools in containers so tests run identically everywhere; Selenium Grid and browsers can be started quickly in containers.

An interface for systems to talk to each other. GET reads, POST creates, PUT replaces, PATCH updates partially and DELETE removes.

switchTo().frame(index, name or element) enters the frame, and switchTo().defaultContent() returns to the main page.

public (everywhere), protected (package and subclasses), default (package) and private (same class), used to control visibility of test utilities.

Code pushed to Git → Jenkins job triggers (webhook or schedule) → mvn clean test with the suite XML → reports and screenshots published → notifications on Slack/email → failures triaged before release.

Lambdas are short anonymous functions; streams process collections declaratively with filter, map and collect, for example filtering link text from a list of elements.

//button[normalize-space()='Login'] //button[contains(text(),'Login')]

Compare effort saved by running automated tests repeatedly against the cost of building and maintaining scripts, counting execution time, defects found earlier and release speed.

Use isDisplayed(), isEnabled() and isSelected() on the WebElement before interacting or asserting.

If the element is <input type="file">, use element.sendKeys("C:/path/file.pdf"). Use the Robot class or AutoIt only as a last resort for OS dialogs.

Do not automate it; ask for a test environment where CAPTCHA is disabled or use test keys, or a bypass token agreed with developers.

Classes such as Integer and Double that wrap primitive types as objects, needed for collections and for parsing text from web elements.

Define parameter name and value in the XML and read them with @Parameters in the test or configuration method.

id, name, className, tagName, linkText, partialLinkText, CSS selector and XPath. Prefer stable ids or CSS, using XPath when needed.

An authorisation framework where a client obtains an access token from an auth server and sends it as a Bearer token; tests fetch and reuse the token in setup.

200 OK, 201 Created, 400 bad request, 401 unauthenticated, 403 forbidden, 404 not found and 500 server error.

Use headers such as Bearer tokens, basic auth, API keys or OAuth flows; fetch a token in a setup step and reuse it.

A subclass redefines a parent method. Frameworks use it to customise base behaviour, such as overriding a wait or click method in a base page class.

Verifying that a provider and consumer agree on request and response formats, using tools like Pact, to catch breaking changes early.

TestNG reports, ExtentReports and Allure give charts, screenshots and logs that are easy to share with the team.

throw actually raises an exception object inside a method; throws declares in the method signature that it may pass an exception to the caller.

Continuous Integration builds and tests every commit, and Continuous Delivery ships automatically. Automated tests give fast feedback and gate releases.

Headless mode or screen resolution, timing issues, environment data, missing dependencies, browser–driver version mismatch or parallel conflicts. Check logs and failure screenshots and make waits robust.

An interface for systems to talk to each other. GET reads, POST creates, PUT replaces, PATCH updates partially and DELETE removes.

WebDriver sends commands over HTTP (W3C protocol) to a browser-specific driver such as chromedriver, which controls the actual browser.

It makes a test run only after specified tests pass, otherwise it is skipped. Use sparingly as it creates coupled tests.

A configuration file to define suites, tests, classes, groups, parameters and parallel execution settings.

Use JavascriptExecutor with window.scrollTo or scrollIntoView, or the Actions class scroll methods in Selenium 4.

Hard assert stops the test at the first failure; SoftAssert collects failures and reports them together when assertAll() is called.

ArrayList and LinkedList for lists, HashSet for unique values, HashMap for key-value test data, and Iterator for traversing them, for example collecting web elements in a list.

A lightweight text format of key-value pairs and arrays used in API requests and responses, validated field by field in tests.

Arrays have a fixed size and can hold primitives; ArrayList grows dynamically, holds objects and offers helper methods.

Set window size explicitly, use proper waits, check animations and viewport differences, and capture screenshots and logs to find timing issues.

Static members belong to the class and are shared by all instances; non-static members belong to each object.

close() closes the current window; quit() closes all windows and ends the driver session.

Use CSS or XPath with contains(), starts-with() or stable attributes, relative axes, or data-test attributes agreed with developers.

Comparable defines the natural order inside the class (compareTo); Comparator defines custom orders externally (compare), useful for sorting test data in several ways.

Use then().statusCode(200).body("data.id", equalTo(5)), or extract() the response and assert fields with JsonPath.

Maven project → POM with a BasePage → driver factory with ThreadLocal → config files → data-driven utilities (Excel/JSON) → TestNG or Cucumber runner → logging → Extent reports with screenshots on failure → Jenkins pipeline.

An abstract class can hold state and concrete methods; an interface defines a contract (with default methods since Java 8). A class extends one abstract class but can implement many interfaces.