Automation Testing Interview Questions for Principal Roles (₹25–30 LPA)

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.

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

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

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

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

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.

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

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

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

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

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

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.

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

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.

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

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

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

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

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

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

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

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

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.

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

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

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

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.

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

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