What is a js timer? How to use js timer-JS Tutorial-php.cn

What is a js timer? How to use js timer

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Release： 2018-11-08 13:52:12

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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);

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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(&#39;php中文欢迎你&#39;);", 2000);
        }
    </script>
</head>
<body>
    <p>php中文欢迎你</p>
</body>
</html>

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The display effect is as follows:

What is a js timer? How to use js timer

(2) setInterval() and clearInterval();

In js, we can use setInterval() to call a function. The syntax is:

var 变量名 = setInterval (code , time);

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setInterval will only execute a piece of code repeatedly, and setTimeout() can only be executed once.

The above is about what is a js timer? A complete introduction to how to use js timer. If you want to know more about JavaScript tutorial, please pay attention to the PHP Chinese website.

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