> For the complete documentation index, see [llms.txt](https://qatesting.gitbook.io/qa/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://qatesting.gitbook.io/qa/automation-testing/flow/selenium/selenium-webdriver/exceptions.md).

# Exceptions

## What are Exceptions? 💥

**Exceptions** are errors that disrupt the normal flow of program execution in Selenium scripts. They indicate something went wrong.

## Why Handle Exceptions? 🛡️

* Avoid script crashes from uncaught exceptions
* Gracefully recover or log issues when they occur
* Improve script robustness by anticipating problems

## What are some common exceptions?

**❌ NoSuchElementException:** The findElement() method could not locate the element using the provided locator. Usually due to an invalid locator.

**❌ NoSuchWindowException:** Trying to switch to a window that does not exist.

**❌ NoSuchFrameException:**

Trying to switch to an iframe that does not exist.

**❌ NoAlertPresentException:** Trying to switch to an alert when no alert is present.

**❌ StaleElementReferenceException:** The element is no longer attached to the DOM. This can happen if the page is reloaded or the element is removed.

**❌ ElementNotVisibleException:** The element is present in the DOM but is not visible, so it cannot be interacted with.

**❌ ElementNotSelectableException:** The element is present but disabled, so it cannot be clicked or selected.

**❌ WebDriverException:** A generic Selenium exception is often due to trying to interact with an element after the browser has closed.

**❌ TimeoutException:** An operation did not complete in the specified time. Commonly encountered with explicit waits.

**❌ InvalidSelectorException:** The provided locator strategy is invalid, such as using an incorrect XPath syntax.

<div data-full-width="true"><figure><img src="https://images.unsplash.com/photo-1512621387945-efb0d554f388?crop=entropy&#x26;cs=srgb&#x26;fm=jpg&#x26;ixid=M3wxOTcwMjR8MHwxfHNlYXJjaHw0fHx3YXJuaW5nfGVufDB8fHx8MTY4OTc1NTI2Mnww&#x26;ixlib=rb-4.0.3&#x26;q=85" alt=""><figcaption></figcaption></figure></div>

So in summary, the most common exceptions you'll encounter while automating web pages using Selenium WebDriver are related to:

* Locating elements
* Switching between windows/frames/alerts
* Element visibility/enablement
* Timeouts
* Invalid locators

## Handling Exceptions in Selenium 🪛

* `try` / `catch` blocks to catch and handle exceptions
* Log exceptions with `e.printStackTrace()` for debugging
* Rethrow exceptions after handling for additional logic
* `finally` block to execute cleanup code like closing browser

## Example Exception Handling ✅

```java
try {

  driver.findElement(By.id("button")).click();

} catch (NoSuchElementException e) {

  System.out.println("Element not found!");
  
} finally {

  driver.quit();

}
```

So in summary, **exception handling** helps **recover and continue** when errors happen in Selenium scripts! 💪