JavaScript while loop

As long as the specified condition is true, the loop can continue to execute the code block.

while loop

The while loop loops through a block of code when a specified condition is true.

Syntax

while (condition)
{
Code to be executed
}

Example

Loop in this example Will continue to run as long as variable i is less than 5:

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>

<p>点击下面的按钮，只要 i 小于 5 就一直循环代码块。</p>
<button onclick="myFunction()">点击这里</button>
<p id="demo"></p>
<script>
function myFunction(){
	var x="",i=0;
	do{
		x=x + "该数字为 " + i + "<br>";
	 i++;
	}
	while (i<5) 
	document.getElementById("demo").innerHTML=x;
}
</script>

</body>
</html>

Continuing Learning

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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<p>点击下面的按钮，只要 i 小于 5 就一直循环代码块。</p>
<button onclick="myFunction()">点击这里</button>
<p id="demo"></p>
<script>
function myFunction(){
    var x="",i=0;
    do{
        x=x + "该数字为 " + i + "<br>";
     i++;
    }
    while (i<5) 
    document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
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