The setInterval and setTimeout methods are commonly used in js code to perform circular events. The details of these methods are not discussed here, but I will briefly share how to do this when you need to stop circular events.
(1) The setInterval method can call a function or evaluate an expression for a specified period (in milliseconds), and the clearInterval method can be used to stop the method. Specific examples are as follows:
<html>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<body>
<input type="text" id="clock" size="50" />
<script language=javascript>
var int=self.setInterval("clock()",50);// every 50 Ms call clock() function
function clock(){
var t=new Date();
document.getElementById("clock").value=t;
}
</script>
<button onclick="window.clearInterval(int)"> stop interval</button>
</body>
</html>Grammar clearInterval (id_of_setinterval)
The parameter id_of_setinterval represents the value of ID returned by setInterval().
The clearInterval() method unsets timeout set by setInterval(); The arguments to the clearInterval() method must be the ID value returned by setInterval().
(2) The setTimeout method is used to call a function or evaluate an expression after a specified number of milliseconds. To stop the method, use the clearTimeout method. Specific examples are as follows:
Tip: setTimeout() executes code only once. If you make multiple calls, use setInterval() or have code itself call setTimeout() again.
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script type="text/javascript">
var c=0;
var t;
function timedCount(){
document.getElementById('txt').value=c;
c=c+1;
t=setTimeout("timedCount()",1000);
}
function stopCount(){
clearTimeout(t);
}
</script>
</head>
<body>
<input type="button" value=" Start counting " onClick="timedCount()">
<input type="text" id="txt">
<input type="button" value=" Stop counting " onClick="stopCount()">
</body>
</html>The clearTimeout() method cancels the timeout set by the setTimeout() method.
Grammar clearTimeout (id_of_settimeout)
The parameter id_of_setinterval represents the value of ID returned by setTimeout(). This value identifies the deferred execution block to cancel.