本文實例講述了JavaScript數組前面插入元素的方法。分享給大家供大家參考。具體如下：
JS數組帶有一個unshift方法可以再數組前面添加若干個元素，下面是詳細的代碼演示
復制代碼代碼如下:
<!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>
執行后數組會變成下面的樣子
Lemon,Pineapple,Banana,Orange,Apple,Mango
unshift在ie8及之前的版本工作有些問題，數組會插入元素，但是返回值是undefined
希望本文所述對大家的javascript程序設計有所幫助。
