Met Win Setinterval

```html Window setInterval() Method | Tutorialspoint

Window setInterval() Method

Example

Pop up "Hello" every three seconds (3000 milliseconds):

setInterval(function(){alert("Hello"); }, 3000);

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Using a code string:

setInterval('alert("Hello");', 3000);

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Definition and Usage

The setInterval() method calls a function or evaluates an expression at specified intervals (in milliseconds).

The setInterval() method continues calling the function until clearInterval() is called or the window is closed. The ID returned from setInterval() can be used as a parameter for the clearInterval() method.

Note: 1000 milliseconds = 1 second.

Note: If you want to execute something only once, use the setTimeout() method.

Browser Support

Method	Internet Explorer	Mozilla Firefox	Chrome	Safari	Opera
setInterval()	1.0	4.0	1.0	1.0	4.0

Syntax

setInterval(code, milliseconds); setInterval(function, milliseconds, param1, param2, ...)

Parameter	Description
code/function	Required. The code to run, or a function to execute.
milliseconds	Required. The interval between each execution of the code or function, in milliseconds.
param1, param2, ...	Optional. Additional parameters passed to the executing function (not supported in Internet Explorer 9 and earlier versions).

Technical Details

Returns:

Returns an ID (number), which can be passed to clearInterval(), clearTimeout() to cancel execution.

More Examples

Example

You can pop up "Hello" every three seconds (3000 milliseconds) by calling a named function:

var myVar; 
function myFunction(){
   myVar = setInterval(alertFunc, 3000); 
}
function alertFunc(){
   alert("Hello!");
}

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Example

Display current time (the setInterval() method will call the function once per second, similar to a watch feature):

var myVar = setInterval(function(){myTimer()}, 1000); 
function myTimer(){
   var d = new Date();
   var t = d.toLocaleTimeString();
   document.getElementById("demo").innerHTML = t;
}

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Example

Use clearInterval() to stop the execution of setInterval:

var myVar = setInterval(function(){myTimer()}, 1000); 
function myTimer(){
   var d = new Date();
   var t = d.toLocaleTimeString();
   document.getElementById("demo").innerHTML = t;
}
function myStopFunction(){
   clearInterval(myVar);
}

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Example

Create a dynamic progress bar using setInterval() and clearInterval():

function move(){
   var elem = document.getElementById("myBar");
   var width = 0;
   var id = setInterval(frame, 10);
   function frame(){
      if(width == 100){
         clearInterval(id);
      } else {
         width++;
         elem.style.width = width + '%';
      }
   }
}

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Example

Change background color every 300 milliseconds:

var myVar = setInterval(function(){setColor()}, 300); 
function setColor(){
   var x = document.body;
   x.style.backgroundColor = x.style.backgroundColor == "yellow" ? "pink" : "yellow";
}
function stopColor(){
   clearInterval(myVar);
}

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Example

Pass parameters to the alertFunc function (not supported in Internet Explorer 9 and earlier versions):

var myVar; 
function myStartFunction(){
   myVar = setInterval(alertFunc, 2000, "", "Google");
}

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However, if you use an anonymous function, all browsers support it:

var myVar; 
function myStartFunction(){
   myVar = setInterval(function(){alertFunc("", "Google"); }, 2000);
}

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Window Object Reference Manual

```

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