Deleting array elements in JavaScript - delete vs splice
javascript 数组中删除元素用 array.splice(start, deleteCount);这个方法。
-----------------------------------------------------
delete
will delete the object property, but will not reindex the array or update its length. This makes it appears as if it is undefined:
> myArray = ['a', 'b', 'c', 'd']
["a", "b", "c", "d"]
> delete myArray[0]
true
> myArray[0]
undefined
Note that it is not in fact set to the value undefined
, rather the property is removed from the array, making it appear undefined. The Chrome dev tools make this distinction clear by printing empty
when logging the array.
> myArray[0]
undefined
> myArray
[empty, "b", "c", "d"]
myArray.splice(start, deleteCount)
actually removes the element, reindexes the array, and changes its length.
> myArray = ['a', 'b', 'c', 'd']
["a", "b", "c", "d"]
> myArray.splice(0, 2)
["a", "b"]
> myArray
["c", "d"]
Deleting array elements in JavaScript - delete vs splice的更多相关文章
- js删除数组中元素 delete 和splice的区别
例如我有一个数组: var array = ["aa","dd","cc","aa"] ,我想删除这个数组的“dd”元素 ...
- [LeetCode] Minimum Moves to Equal Array Elements II 最少移动次数使数组元素相等之二
Given a non-empty integer array, find the minimum number of moves required to make all array element ...
- [LeetCode] Minimum Moves to Equal Array Elements 最少移动次数使数组元素相等
Given a non-empty integer array of size n, find the minimum number of moves required to make all arr ...
- LeetCode Minimum Moves to Equal Array Elements II
原题链接在这里:https://leetcode.com/problems/minimum-moves-to-equal-array-elements-ii/ 题目: Given a non-empt ...
- LeetCode Minimum Moves to Equal Array Elements
原题链接在这里:https://leetcode.com/problems/minimum-moves-to-equal-array-elements/ 题目: Given a non-empty i ...
- LeetCode 453 Minimum Moves to Equal Array Elements
Problem: Given a non-empty integer array of size n, find the minimum number of moves required to mak ...
- javascript中的splice方法介绍&示例
javascript 中的 splice 方法很强大,它可以用于插入.删除或替换数组的元素. 下面来一一介绍! 删除:用于删除元素,两个参数,第一个参数(要删除第一项的位置),第二个参数(要删除的项数 ...
- Leetcode-462 Minimum Moves to Equal Array Elements II
#462. Minimum Moves to Equal Array Elements II Given a non-empty integer array, find the minimum n ...
- javascript delete方法
学习delete可以参考下面两个博客,写的都很好,本文大部分参考与以下两个博客 http://www.cnblogs.com/windows7/archive/2010/03/28/1698387.h ...
随机推荐
- centos7中将python2.7.5版本升级到3.x版本
一.安装gcc源码编译器 yum -y install gcc gcc-c++ pcre-devel zlib-devel openssl-devel 二.下载python软件包 wget https ...
- 组队赛Day1第一场 GYM 101350 F. Monkeying Around(线段树)
[题目大意] 有n只猴子坐在树上,m个笑话. 给出每个讲这个笑话的猴子的编号,笑话的编号,和笑话的影响半径. 如果一个树上的猴子听了没听过的笑话,会掉到树下.如果听过并且在树下,就会爬到树上. 问最后 ...
- 算法学习记录-排序——冒泡排序(Bubble Sort)
冒泡排序应该是最常用的排序方法,我接触的第一个排序算法就是冒泡,老师也经常那这个做例子. 冒泡排序是一种交换排序, 基本思想: 通过两两比较相邻的记录,若反序则交换,知道没有反序的记录为止. 例子: ...
- linux下防火墙iptables原理及使用
iptables简介 netfilter/iptables(简称为iptables)组成Linux平台下的包过滤防火墙,与大多数的Linux软件一样,这个包过滤防火墙是免费的,它可以代替昂贵的商业防火 ...
- 03004_Web开发
1.Web开发中常见的概念 (1)B/S系统和C/S系统 ①Brower/Server:浏览器 服务器 系统------网站: ②Client/Server:客户端 服务器 系统------QQ.大型 ...
- js 获取json对象的Key、value
<script type="text/javascript"> getJson('age'); function getJson(key){ var jsonObj={ ...
- java编程思想阅读记录
第五章:初始化与清理 1.构造器确保初始化 构造器采用与类名相同的方法. 创建对象时,将会为对象分配存储空间,并调用相应的构造器.这就确保了在你能操作对象之前,它就已经恰当的被初始化了. 垃圾回收器负 ...
- LINQ学习笔记 Join 与 Group join
LINQ中的Join对应T-SQL中的内连接,并无左连接的方法,当然也没有右连接. 要达成Left join必须依靠GroupJoin来完成. GroupJoin顾名思义就是先集团在做加入,加入的不同 ...
- WebLoad XML-parser methods
WebLOAD provides an embedded, third-party XML parser object to improve the multi-platform support fo ...
- C++ 中的 C_str() 函数用法
转中转 ~\(≧▽≦)/~ :http://blog.csdn.net/nancy_m/article/details/7583550 语法: const char *c_str(); c_str() ...