Prepare for Your Selenium Interview With These 10 Questions

Selenium, an open-source tool for automating testing web applications, is used widely. The ease of use and flexibility of the framework has made it a favorite among developers and QA testers. Many companies are now looking for Selenium experts. If you're preparing Selenium interview questions, the below tricky questions will be really helpful. In this article, we'll be discussing ten tricky Selenium interview questions.

1. What are the different types of locators in Selenium WebDriver?

Answer: The different types of locators in Selenium are ID, Name, Class Name, Tag Name, Link Text, Partial Link Text, CSS Selector, and XPath. These locators are used to identify web elements on a given web page.

2. What is the difference between findElement() and findElements() in Selenium?

Answer: findElement() is used to find the first web element matching the specified locator on a web page, while findElements() is used to find all the web elements matching the specified locator on a web page. The findElement() method returns a single WebElement object, while the findElements() method returns a list of WebElement objects.

3. What is the difference between the two waits - Implicit wait and Explicit wait?

Answer: Implicit wait is a global setting that waits for a certain amount of time before throwing an exception if an element is not found. Explicit wait, on the other hand, waits for a specific condition to be met before proceeding to the next step. Implicit wait is set at the beginning of the test and is applied to all the elements on that web page, whereas explicit wait is set for a specific element or condition.

4. What is the difference between close() and quit() method?

Answer: driver.close() closes the current browser window, while driver.quit() closes all the browser windows and ends the WebDriver session. If there are multiple browser windows open, driver.close() will only close the current window, while driver.quit() will close all the windows and end the session.

5. How do you handle alerts in Selenium WebDriver?

Answer: To handle alerts in Selenium, we use the Alert interface provided by WebDriver. We can use the accept() method to accept the alert, the dismiss() method to dismiss the alert, and the getText() method to get the text of the alert.

6. How do you handle frames in Selenium WebDriver?

Answer: To handle frames in Selenium, we use the switchTo() method provided by WebDriver. We can simply switch to a frame by using its index, name, or WebElement. We can switch back to the default content using the defaultContent() method.

7. How do you handle dropdowns or Select elements?

Answer: To handle dropdowns in Selenium, we use the Select class provided by WebDriver. We can select an option by using its value, index, or visible text. We can also get all the options in a dropdown using the getOptions() method.

8. How do you handle multiple windows?

Answer: Handling multiple windows in Selenium can be tricky, but it is an essential part of automated testing. There are different scenarios where a web application may open multiple windows, such as pop-ups, advertisements, or multiple tabs. In Selenium, there are several ways to handle multiple windows:

getWindowHandles() method:

The getWindowHandles() method returns a set of all the window handles. You can switch between the windows using the switchTo() method. The syntax for this method is as follows:

Set<String> handles = driver.getWindowHandles(); Iterator<String> it = handles.iterator(); String mainWindow = it.next(); String childWindow = it.next(); driver.switchTo().window(childWindow);

In this example, we are switching to the second available window by retrieving the second window handle from the set.

getWindowHandle() method:

The getWindowHandle() method returns the handle of the current window. You can use this method to switch back to the main window after performing an action on the child window. The syntax for this method is:

mainWindow = driver.getWindowHandle();

In this example, we will be switching back to the main window by retrieving the main window handle and using the switchTo() method.

Using window title:

If you know the title of the window that you want to switch to, you can use it to switch between the windows. The syntax for this method is as follows:

for (String handle : driver.getWindowHandles()) { driver.switchTo().window(handle); if (driver.getTitle().equals("New Window Title")) { break; } }

In this example, we are iterating through all the windows and then switching to each window and checking if the window title matches the expected title.

Using window index:

If you know the index of the window that you want to switch to, you can simply use it to switch between the windows. The syntax for this method is:

List<String> windows = new ArrayList<String>(driver.getWindowHandles()); driver.switchTo().window(windows.get(1));

In this example, we are storing all the window handles in a list and then switch to the second window by specifying the index.

Selenium's handling of multiple windows requires careful planning and execution. When dealing with pop-ups or advertisements, it's crucial to know which window to select. These methods will help you manage multiple windows efficiently and improve the accuracy and reliability of your test scripts.

9. What is Page Object Model?

Answer: Page Object Model is a Selenium design pattern that makes test scripts easier to read, maintain, and reuse. In POM, each web page is represented by a Java class, and the web elements are defined as instance variables. Methods are used to define the actions that can be performed on web elements.

10. How do you handle synchronization issues in Selenium WebDriver?

Answer: Selenium's synchronization problems must be resolved to ensure your test scripts are accurate and run smoothly. Synchronization problems occur when an automation script runs faster than the page under test, resulting in errors like element not found and stale reference. There are two different types of waits in Selenium that can be applied to handle synchronization problems: Implicit and Explicit.

Implicit Wait:

An implicit wait instructs the WebDriver to wait for a certain amount of time before throwing a NoSuchElementException if the element is not found on the web page. The maximum wait time can be set at the start of the script. It applies globally to all web elements. The syntax of implicit wait is:

driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);

This sets the implicit wait time to 10 seconds.

Explicit Wait:

An explicit wait instructs WebDriver that it must wait until a condition is met before moving on to the next stage. This is used when an implicit wait is insufficient or when more detailed control is needed. Some of the most common conditions used for explicit waiting are:

elementToBeClickable() – Waits for the element to be clickable

visibilityOfElementLocated() – Waits for the element to be visible on the web page

textToBePresentInElement() – Waits for the specified text to be present in the element

The syntax for explicit wait is:

WebDriverWait(driver, 10); wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("element_id")));

This will set an explicit wait for 10 seconds for the element with the id 'element_id' to be visible on the web page.

Use of waits in Selenium can be used to improve reliability and stability. It's important, however, to use them judiciously. They can cause the test execution to slow down.

We have now concluded our article on the Top 10 Selenium Interview Questions. Please let us know if we missed any frequently-asked interview questions about Selenium.