在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(cainiaoplay.com)</title>
</head>
<body>

<p>点击按钮复制数组的前面两个元素到第三和第四个位置上。</p>

<button onclick="myFunction()">点我</button>

<p id="demo"></p>

<p><strong>注意:</strong> IE 11 及更早版本不支持 copyWithin() 方法。</p>
	
<script>
var fruits = ["Banana", "Orange", "Apple", "Mango", "Kiwi", "Papaya"];
document.getElementById("demo").innerHTML = fruits;

function myFunction() {  
    document.getElementById("demo").innerHTML = fruits.copyWithin(2,0,2);
}
</script>

</body>
</html>
源代码

动行结果
