QA Automation – Core Java & Selenium 𝗧𝗲𝗰𝗵𝗻𝗶𝗰𝗮𝗹 Interview Questions

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1️⃣ What are the differences between findElement() and findElements()?

Sample Answer:

• findElement() returns a single WebElement.
• If the element is not found, it throws NoSuchElementException.
• findElements() returns a List<WebElement>.
• If no elements are found, it returns an empty list (does not throw exception).
• findElement() is used when exactly one element is expected.
• findElements() is used for multiple elements like dropdown options, lists, tables.

Example:

WebElement loginBtn = driver.findElement(By.id("login"));
List<WebElement> links = driver.findElements(By.tagName("a"));

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2️⃣ How do you handle dynamic web elements in Selenium?

Sample Answer:

I handle dynamic elements using:

• Dynamic XPath: using contains(), starts-with()
• CSS Selectors with partial attributes
• Explicit Waits for dynamic loading
• Handling StaleElementReferenceException with re-locating element

Example:

driver.findElement(By.xpath("//input[contains(@id,'user')]"));

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3️⃣ Explain different types of waits used in Selenium.

Sample Answer:

• Implicit Wait – Applied globally, waits for elements to be present.
• Explicit Wait (WebDriverWait) – Waits for a specific condition.
• Fluent Wait – Custom polling time, ignores specific exceptions.

Example of Explicit Wait:

WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(10));
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("submit")));

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4️⃣ What’s the difference between XPath and CSS Selector?

Sample Answer:

XPath	CSS Selector
Can traverse forward & backward	Only forward traversal
Supports contains(), text()	No text() support
Slower compared to CSS	Generally faster
More powerful for complex DOM	Cleaner & shorter syntax

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5️⃣ How do you handle multiple windows/tabs in Selenium?

Sample Answer:

I use getWindowHandles() to get all window IDs and switch using switchTo().window().

String parent = driver.getWindowHandle();
Set<String> windows = driver.getWindowHandles();

for(String window : windows){
 if(!window.equals(parent)){
 driver.switchTo().window(window);
 }
}

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6️⃣ How do you design a Page Object Model (POM) framework?

Sample Answer:

In POM framework:

• Each page is represented as a separate class.
• Web elements are declared using @FindBy.
• Page methods contain business logic.
• Test classes call page methods.
• Common utilities like BaseTest, DriverFactory are separated.

Advantages:

• Code reusability
• Maintainability
• Separation of concerns

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7️⃣ What is the use of final, static, and this keywords in Java?

Sample Answer:

• final – used for constants, preventing inheritance or method overriding.
• static – belongs to class, shared across objects.
• this – refers to current class instance variable.

Example:

public class Test {
 static int count = 0;
 final int MAX = 10;

```
public void setCount(int count){
 this.count = count;
}
```

}

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8️⃣ Explain Collection Framework — where have you used HashMap or ArrayList in your automation?

Sample Answer:

I have used:

• ArrayList – storing multiple WebElements or test data rows.
• HashMap – storing key-value pairs like username-password, column-value mapping.

Example:

HashMap<String, String> userData = new HashMap<>();
userData.put("username", "admin");
userData.put("password", "admin123");

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9️⃣ How do you handle exceptions in Selenium scripts?

Sample Answer:

• Using try-catch blocks
• Using throws declaration
• Custom exception handling in framework
• Retry mechanism for flaky tests
• Logging errors using Log4j

Example:

try {
 driver.findElement(By.id("login")).click();
} catch (NoSuchElementException e) {
 System.out.println("Element not found");
}

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🔟 What’s your approach to data-driven testing using TestNG or Excel?

Sample Answer:

I use @DataProvider in TestNG to pass multiple test data sets.

For Excel integration:

• Use Apache POI to read Excel file.
• Store data in Object[][] format.
• Pass to @DataProvider method.

Example:

@DataProvider(name="loginData")
public Object[][] getData(){
 return new Object[][] {
 {"admin","admin123"},
 {"user","user123"}
 };
}