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What is a js timer? How to use js timer
- 云罗郡主Original
- 2018-11-08 13:51:578890browse
Many people will encounter the carousel effect of pictures and play it for two minutes. At this time, a timer will be needed. So what is a js timer? Let's explain how to use js timer.
1: What is a js timer
js timer is a method of using js to achieve timing. There are many uses for timers on websites. , the production of many online clocks, the implementation of picture carousels, and some advertising pop-ups, anything that can be executed automatically can be related to timers.
2: Two methods used by js timer
(1)setTimeout() and clearTimeout();
In js, we You can use setTimeout() and clearTimeout to set the function, and the function is called once and cannot be executed repeatedly. ClearTimeout() can cancel the execution. The syntax is:
var 变量名 = setTimeout(code , time);
The above syntax is to call a function with a variable Name, we can set the time to indicate how long it will take before the content in the code will be automatically automatically generated.
For example:
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script type="text/javascript">
window.onload = function () {
setTimeout("alert('php中文欢迎你');", 2000);
}
</script>
</head>
<body>
<p>php中文欢迎你</p>
</body>
</html>The display effect is as follows:
(2) setInterval() and clearInterval();
In js, we can use setInterval() to call a function. The syntax is:
var 变量名 = setInterval (code , time);
setInterval will only execute a piece of code repeatedly, and setTimeout() can only be executed once.
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