代码示例:(标识:eg_js_array_add_length)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript 数组</h1>

<p>length 属性提供了一种在不使用 push() 方法的情况下将新元素附加到数组的简便方法。</p>

<button onclick="myFunction()">试一试</button>

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

<script>
var fruits = ["Banana", "Orange", "Apple", "Mango"];
document.getElementById("demo").innerHTML = fruits;

function myFunction() {
  fruits[fruits.length] = "Lemon";
  document.getElementById("demo").innerHTML = fruits;
}
</script>

</body>
</html>
运行结果: