JavaScript 如何清空数组? 下面本篇文章就来给大家介绍几种使用 JavaScript 清空数组的方法, 希望对大家有所帮助.
方法 1: 使用 length 属性将数组的长度设置为零
length 属性可设置或返回数组中元素的数目.
示例:
- <!DOCTYPE html>
- <HTML>
- <head>
- <meta charset="utf-8">
- <title>JavaScript 清空数组 </title>
- </head>
- <body style = "text-align:center;">
- <p id = "up"></p>
- <button onclick="empty()">
单击可清空
- </button>
- <p id = "down" style="color: green"></p>
- <p id = "down1" style="color: green"></p>
- <!-- 将数组大小设置为零 -->
- <script>
- var GFG_Array = [1, 2, 3, 4, 5];
- var up = document.getElementById("up");
- up.innerHTML = "GFG_Array:"+GFG_Array;
- var down = document.getElementById("down");
- down.innerHTML = "GFG_Array 的长度为:"
- + GFG_Array.length;
- function empty() {
- GFG_Array.length = 0;
- down = document.getElementById("down");
- down.innerHTML = "GFG_Array 的长度为:"
- + GFG_Array.length;
- down1 = document.getElementById("down1");
- down1.innerHTML = "GFG_Array:"+GFG_Array;
- }
- </script>
- </body>
- </HTML>
效果图:
方法 2: 使用 pop 方法连续删除数组元素, 得到空数组
pop() 方法用于删除并返回数组的最后一个元素, 把数组长度减 1, 并且返回它删除的元素的值. 如果数组已经为空, 则 pop() 不改变数组, 并返回 undefined 值.
例:
- <!DOCTYPE HTML>
- <HTML>
- <head>
- <meta charset="utf-8">
- <title>JavaScript 清空数组 </title>
- </head>
- <body style = "text-align:center;">
- <p id = "up"></p>
- <button onclick="empty()">
单击可清空
- </button>
- <p id = "down" style="color: green"></p>
- <p id = "down1" style="color: green"></p>
- <!-- 将数组大小设置为零 -->
- <script>
- var GFG_Array = [1, 2, 3, 4, 5];
- var up = document.getElementById("up");
- up.innerHTML = "GFG_Array:"+GFG_Array;
- var down = document.getElementById("down");
- down.innerHTML = "GFG_Array 的长度为:"
- + GFG_Array.length;
- function empty() {
- while(GFG_Array.length> 0) {
- GFG_Array.pop();
- }
- down = document.getElementById("down");
- down.innerHTML = "GFG_Array 的长度为:"
- + GFG_Array.length;
- down1 = document.getElementById("down1");
- down1.innerHTML = "GFG_Array:"+GFG_Array;
- }
- </script>
- </body>
- </HTML>
效果图:
注: 这种方法比其他方法花费的时间更多, 而且不太受欢迎.
来源: http://www.css88.com/qa/javascript/11262.html