How can we handle web based pop up?

WebDriver offers the users with a very efficient way to handle these pop ups using Alert interface .There are the four methods that we would be using along with the Alert interface.

• void dismiss() – The accept() method clicks on the “Cancel” button as soon as the pop up window appears.
• void accept() – The accept() method clicks on the “Ok” button as soon as the pop up window appears.
• String getText() – The getText() method returns the text displayed on the alert box.
• void sendKeys(String stringToSend) – The sendKeys() method enters the specified string pattern into the alert box.

Syntax:
// accepting javascript alert 
                Alert alert = driver.switchTo().alert();
alert.accept();