Home > Web Front-end > JS Tutorial > body text

Detailed explanation of the methods of Array object extension and String object extension in JS

怪我咯
Release: 2017-07-04 15:18:48
Original
1182 people have browsed it

This article mainly introduces the detailed explanation of the Array object expansion and String object expansion related information in JS. Friends who need it can refer to it

No more nonsense, I will give it to you directly The array object expansion code is shown above. The specific code is as follows:

/**
* Created by laixiangran on 2016/01/07.
* Array扩展
*/
(function() {
// 遍历数组
if (typeof Array.prototype.forEach != "function") {
Array.prototype.forEach = function (fn, context) {
for (var i = 0; i < this.length; i++) {
if (typeof fn === "function" && Object.prototype.hasOwnProperty.call(this, i)) {
fn.call(context, this[i], i, this);
}
}
};
}
// 让数组中的每一个元素调用给定的函数,然后把得到的结果放到新数组中返回
if (typeof Array.prototype.map != "function") {
Array.prototype.map = function (fn, context) {
var arr = [];
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
arr.push(fn.call(context, this[k], k, this));
}
}
return arr;
};
}
// 把符合条件的元素放到一个新数组中返回
if (typeof Array.prototype.filter != "function") {
Array.prototype.filter = function (fn, context) {
var arr = [];
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
fn.call(context, this[k], k, this) && arr.push(this[k]);
}
}
return arr;
};
}
// 如果数组中的每个元素都能通过给定的函数的测试,则返回true,反之false
if (typeof Array.prototype.every != "function") {
Array.prototype.every = function (fn, context) {
var passed = true;
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
if (passed === false) break;
passed = !!fn.call(context, this[k], k, this);
}
}
return passed;
};
}
// 类似every函数,但只要有一个通过给定函数的测试就返回true
if (typeof Array.prototype.some != "function") {
Array.prototype.some = function (fn, context) {
var passed = false;
if (typeof fn === "function") {
for (var k = 0, length = this.length; k < length; k++) {
if (passed === true) break;
passed = !!fn.call(context, this[k], k, this);
}
}
return passed;
};
}
// 返回元素在数组的索引,没有则返回-1,从左到右
if (typeof Array.prototype.indexOf != "function") {
Array.prototype.indexOf = function (item, index) {
var n = this.length,
i = index == null ? 0 : index < 0 ? Math.max(0, n + index) : index;
for (; i < n; i++) {
if (i in this && this[i] === item) {
return i
}
}
return -1
};
}
// 返回元素在数组的索引,没有则返回-1,从右到左
if (typeof Array.prototype.lastIndexOf != "function") {
Array.prototype.lastIndexOf = function (item, index) {
var n = this.length,
i = index == null ? n-1 : index < 0 ? Math.max(0, n + index) : index;
for (; i >= 0; i--) {
if (i in this && this[i] === item) {
return i;
}
}
return -1;
};
}
// 让数组元素依次调用给定函数,最后返回一个值(从左到右)
if (typeof Array.prototype.reduce != "function") {
Array.prototype.reduce = function (callback, initialValue) {
var previous = initialValue, k = 0, length = this.length;
if (typeof initialValue === "undefined") {
previous = this[0];
k = 1;
}
if (typeof callback === "function") {
for (k; k < length; k++) {
this.hasOwnProperty(k) && (previous = callback(previous, this[k], k, this));
}
}
return previous;
};
}
// 让数组元素依次调用给定函数,最后返回一个值(从右到左)
if (typeof Array.prototype.reduceRight != "function") {
Array.prototype.reduceRight = function (callback, initialValue) {
var length = this.length, k = length - 1, previous = initialValue;
if (typeof initialValue === "undefined") {
previous = this[length - 1];
k--;
}
if (typeof callback === "function") {
for (k; k > -1; k-=1) {
this.hasOwnProperty(k) && (previous = callback(previous, this[k], k, this));
}
}
return previous;
};
}
// 去掉重复项(唯一性),返回新数组
if (typeof Array.prototype.uniq != "function") {
Array.prototype.uniq = function() {
var arr = [];
arr[0] = this[0];
for (var i = 1; i < this.length; i++) {
if (arr.indexOf(this[i]) == -1) {
arr.push(this[i]);
}
}
return arr;
};
}
// 指定删除数组中某值
if (typeof Array.prototype.remove != "function") {
Array.prototype.remove = function(item) {
for (var i = this.length; i >= 0; i--) {
if (item === this[i]) {
this.splice(i, 1);
}
}
return this;
};
}
// 打乱数组顺序
if (typeof Array.prototype.shuffle != "function") {
Array.prototype.shuffle = function() {
var i = this.length;
while (i) {
var j = Math.floor(Math.random()*i);
var t = this[--i];
this[i] = this[j];
this[j] = t;
}
return this;
};
}
// 求数组的最大值
if (typeof Array.prototype.max != "function") {
Array.prototype.max = function() {
return Math.max.apply({}, this)
};
}
// 求数组的最小值
if (typeof Array.prototype.max != "function") {
Array.prototype.min = function() {
return Math.min.apply({}, this)
};
} 

// 判断是否为数组
if (typeof Array.prototype.isArray != "function") {
Array.prototype.isArray = function() {
return Object.prototype.toString.apply(this) === "[object Array]";
};
} 
}());
Copy after login

The following is the string object expansion code as follows:

/**
* Created by laixiangran on 2015/12/12.
* String扩展
*/
(function() {
// 十六进制颜色值的正则表达式
var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
// RGB颜色转换为16进制
if (typeof String.prototype.rgbToHex != "function") {
String.prototype.rgbToHex = function() {
var that = this;
if (/^(rgb|RGB)/.test(that)) {
var aColor = that.replace(/(?:\(|\)|rgb|RGB)*/g,"").split(",");
var strHex = "#";
for (var i=0; i
Copy after login

The above is the detailed content of Detailed explanation of the methods of Array object extension and String object extension in JS. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!