1、For 循环：单击按钮将代码块循环执行5次
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>单击按钮将代码块循环执行5次。</p>
<button onclick="myFunction()">点我</button>
<p id="demo"></p>
<script>
function myFunction(){
var x="",i;
for (i=0;i<5;i++){
x=x+"这个数字是"+i+"<br>";
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
2、For 循环：单击按钮将HTML标题设置从1到6的样式显示
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>单击按钮将HTML标题设置从1到6的样式显示</p>
<button onclick="myFunction()">点我点我</button>
<div id="demo"></div>
<script>
function myFunction(){
var x="",i;
for (i=1;i<6;i++){
x=x+"<h"+i+">Heading"+i+"</h"+i+">";
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
3、While 循环：只要 i 小于 6就一直循环代码块
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>点击下面的按钮，只要 i 小于 6就一直循环代码块。</p>
<button onclick="myFunction()">点我点我</button>
<p id="demo"></p>
<script>
function myFunction(){
var x="",i=0;
while (i<6){
x=x+"该数字为"+i+"<br>";
i++;
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
4、Do while 循环：i 小于 6就一直循环代码块
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>点击下面的按钮，只要 i 小于 6就一直循环代码块。</p>
<button onclick="myFunction()">点我点我</button>
<p id="demo"></p>
<script>
function myFunction(){
var x="",i=0;
do {
x=x+"该数字为"+i+"<br>";
i++;
}
while (i<6)
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
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