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Summary of common methods in js function projects

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Release: 2018-06-04 17:42:06
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This time I will bring you a summary of common methods in js function projects, and what are the common precautions in js function projects. Here are practical cases, let’s take a look.
1. Object declaration
1. Use keyword declaration

var obj = new Object;
obj.name = '';
obj['sex'] = '';
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2. Use json format

var obj = {'key':'val'};
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3. Use constructor

function obj(){
this.name = '';
}
var p = new obj();
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Object access

.
[]
this
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2. Object traversal

for()  遍历数组
for..in 遍历对象
with(obj){
}
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3. Built-in object
String object
Statement

var str = new String();
var str = '';
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Method

trim()  清除两侧的空白
charAt()  获取字符串指定位置上的字符
indexOf()  获取指定字符或者字符串首次出现的位置
lastIndexOf()  获取指定字符或者字符串最后一次出现的位置
concat()  连接两个或者多个字符串
slice()  截取字符串 从开始到结束   要前不要后
split()  按照指定的字符或者字符串来拆分字符串数组
substr()  截取字符串
toLowerCase()  将字符串转化成小写
toUpperCase()  将字符串转化成大写
replace()  替换一个与正则表达式匹配的子字符串
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Array object
Declaration

var arr = [];
var arr = new Array()
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Function

concat()  连接一个或多个数组
join()  将数组元素连接起来转化成一个字符串
reverse()  翻转数组的元素
slice()  返回数组的一部分
sort()  对数组元素进行排序
splice()  插入、删除或替换数组的元素
push()  从数组的尾部压入元素
pop()  从数组的尾部删除元素
unshift()  从数组的头部插入一个元素
shift()  从数组的头部删除一个元素
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ArrayNotes
1. Arrays cannot be used [] Direct assignment
2. The subscript has continuity
3. No associative array
4. Two-dimensional arrayUse

var a = [];
a[0] = [];
a[1] = []
[
[],
[],
[],
]
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Time object
Instantiation

var date = new Date;
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Method

getFullYear() 获取年份
getMonth()  获取月份
获取当前的月份 +1
getDate()  获取天
getHours()  获取小时  
getMinutes()  获取分钟
getSeconds()  获取秒  
getDay()  获取星期
0-6   对应着星期日至星期六
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Mathematical Object

Math
round()  浮点数四舍五入
max()  获取最大值
min()  获取最小值
abs()  绝对值
floor()  舍去取整
ceil()   上取整(进一取整)
pow()   获取n次幂
sqrt()  求平方根
random()  获取0-1之间的随机数
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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related matters on the php Chinese website article!

Recommended reading:

Summary of inheritance methods of JS (with cases)

Detailed explanation of JS framework library use cases

The above is the detailed content of Summary of common methods in js function projects. For more information, please follow other related articles on the PHP Chinese website!

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