Top questions with answers asked in MNC on Selenium

Selenium interview questions commonly asked in top MNCs, along with their answers:

1. What is Selenium, and what are its advantages?
   • Answer: Selenium is an open-source automation testing tool used for automating web applications. It provides a suite of tools for different testing needs:
     • Selenium WebDriver: For automating web browsers across multiple platforms.
     • Selenium IDE: For recording and playing back tests in the browser.
     • Selenium Grid: For running tests in parallel across different browsers and platforms. Advantages of Selenium include:
     • Supports multiple programming languages (Java, Python, C#, etc.).
     • Supports multiple browsers (Chrome, Firefox, Safari, etc.).
     • Supports parallel test execution.
     • Integrates well with other testing frameworks and tools.
     • Large community support and extensive documentation.
2. What are the different locators used in Selenium WebDriver?
   • Answer: Locators are used to identify web elements on a web page. Selenium WebDriver supports various locators, including:
     • ID: Finds an element by its ID attribute.
     • Name: Finds an element by its name attribute.
     • XPath: Finds an element using XML path expressions.
     • CSS Selector: Finds an element using CSS selectors.
     • Link Text: Finds a link element by its visible text.
     • Partial Link Text: Finds a link element by a part of its visible text.
     • Class Name: Finds an element by its class attribute.
3. What is the difference between implicit wait and explicit wait in Selenium?
   • Answer:
     • Implicit Wait: Implicit wait instructs the WebDriver to wait for a certain amount of time before throwing a NoSuchElementException if an element is not immediately present. It is set globally for the entire duration of the WebDriver instance.
     • Explicit Wait: Explicit wait is used to wait for a certain condition (e.g., presence of an element, visibility of an element, etc.) to occur before proceeding with the next steps in the test script. It is applied to specific elements with a defined timeout.
4. How do you handle dynamic elements in Selenium WebDriver?
   • Answer: Dynamic elements are elements on a web page whose attributes or values change dynamically based on user interactions or other factors. To handle dynamic elements in Selenium WebDriver, we can use techniques such as:
     • Explicit Waits: Wait for the element to become stable using WebDriverWait with ExpectedConditions.
     • Implicit Waits: Set a global wait time to allow sufficient time for dynamic elements to load.
     • Using Unique Identifiers: Identify other stable elements nearby and traverse the DOM to reach the dynamic element.
     • JavascriptExecutor: Execute JavaScript to interact with the dynamic element directly.
5. What are Page Object Models (POM) in Selenium, and why are they used?
   • Answer: Page Object Model (POM) is a design pattern used in Selenium automation testing to create an object repository for web elements on a web page. Each web page in the application is represented as a separate class, and the web elements and their related actions are encapsulated within that class. POM promotes code reusability, maintainability, and reduces code duplication. It enhances test script readability and makes test maintenance easier when UI changes occur.