<html><body><h2>JavaScript 数组方法</h2> <h2>unshift()</h2><p>unshift() 方法返回新数组的长度：</p><p id="demo1"></p><p id="demo2"></p><p id="demo3"></p><script>var fruits = ["香蕉","橙子","苹果","芒果"];document.getElementById("demo1").innerHTML = fruits;document.getElementById("demo2").innerHTML = fruits.unshift("Lemon");document.getElementById("demo3").innerHTML = fruits;</script><p><b>注意：</b> unshift() 方法在 Internet Explorer 8 及更早版本中无法正常工作，将插入值，但返回值将是<em>undefined</em>。</p></body></html>