本文实例讲述了JavaScript数组前面插入元素的方法。分享给大家供大家参考。具体如下：
JS数组带有一个unshift方法可以再数组前面添加若干个元素，下面是详细的代码演示
复制代码代码如下:
<!DOCTYPE html>
<html>
<body>
<p id="demo">Click the button to add elements to the array.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.unshift("Lemon","Pineapple");
var x=document.getElementById("demo");
x.innerHTML=fruits;
}
</script>
<p><b>Note:</b> The unshift() method does not work properly in Internet Explorer 8 and earlier, the values will be inserted, but the return value will be <em>undefined</em>.</p>
</body>
</html>
<html>
<body>
<p id="demo">Click the button to add elements to the array.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.unshift("Lemon","Pineapple");
var x=document.getElementById("demo");
x.innerHTML=fruits;
}
</script>
<p><b>Note:</b> The unshift() method does not work properly in Internet Explorer 8 and earlier, the values will be inserted, but the return value will be <em>undefined</em>.</p>
</body>
</html>
执行后数组会变成下面的样子
Lemon,Pineapple,Banana,Orange,Apple,Mango
unshift在ie8及之前的版本工作有些问题，数组会插入元素，但是返回值是undefined
希望本文所述对大家的javascript程序设计有所帮助。
