window.setTimeout() or setTimeout()

setTimeout() executes code after a specified amount of time.

setTimeout() method accepts two arguments:
the code to execute
the number of time (in milliseconds) to wait.

The first argument can be either a string containing JavaScript code or a function.

The following code runs an document.writeln after 1 second:

 
<!DOCTYPE HTML> 
<html> 
    <head> 
        <title>Example</title> 
    </head> 
    <body> 
        <script type="text/javascript"> 
    setTimeout(function() { 
                      document.writeln("Hello world!"); 
                   }, 
                   1000
    ); 


        </script> 
    </body> 
</html>

Click to view the demo

setTimeout() returns a numeric ID for the timeout. The ID can be used to cancel the timeout. To cancel a pending timeout, use the clearTimeout() method and pass in the timeout ID:

 
<!DOCTYPE HTML> 
<html> 
    <head> 
        <title>Example</title> 
    </head> 
    <body> 
        <script type="text/javascript"> 
            var timeoutId = setTimeout(function() { 
                document.writeln("Hello world!"); 
                }, 1000); 
            
            clearTimeout(timeoutId); 

        </script> 
    </body> 
</html>

Click to view the demo

The following code set the timeout according to a value:

 
<!DOCTYPE HTML> 
<html> 
    <head> 
        <title>Example</title> 
    </head> 
    <body> 
        <script type="text/javascript"> 
                var num = 0; 
                var max = 10; 
                function incrementNumber() { 
                    document.writeln(num++);  
                    //if the max has not been reached, set another timeout 
                    if (num < max) { 
                        setTimeout(incrementNumber, 500); 
                    } else { 
                        document.writeln("Done"); 
                    } 
                } 
                setTimeout(incrementNumber, 500); 

        </script> 
    </body> 
</html>

Click to view the demo