Cognizant Automation Testing Interview Questions & Answers

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

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

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

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

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

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

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

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.

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.

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.

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

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.

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

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

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

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

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 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.

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

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.

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

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

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.

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

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

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

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

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

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

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

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.

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.

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.

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

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.

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

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

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

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

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.

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.

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

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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.

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

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.

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

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

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.