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<!DOCTYPE html> <html> <body> <h1>JavaScript 数组方法</h1> <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 = ["Banana", "Orange", "Apple", "Mango"]; document.getElementById("demo1").innerHTML = fruits; document.getElementById("demo2").innerHTML = fruits.unshift("Lemon"); document.getElementById("demo3").innerHTML = fruits; </script> <p><b>注释：</b>unshift() 方法在 Internet Explorer 8 及更早版本中无法正常工作，会插入值，但返回值将是 <em>undefined</em>。</p> </body> </html>
运行结果
