Rumah >hujung hadapan web >tutorial js >详解JS中Array对象扩展与String对象扩展的方法
这篇文章主要介绍了详解JS中Array对象扩展与String对象扩展的相关资料,需要的朋友可以参考下
废话不多说了,直接给大家上array对象扩展代码了,具体代码如下所示:
/** * 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]"; }; } }());
下面是string对象扩展代码如下所示:
/** * 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<aColor.length; i++) { var hex = Number(aColor[i]).toString(16); if (hex === "0") { hex += hex; } strHex += hex; } if (strHex.length !== 7) { strHex = that; } return strHex; }else if (reg.test(that)) { var aNum = that.replace(/#/,"").split(""); if (aNum.length === 6){ return that; }else if (aNum.length === 3) { var numHex = "#"; for (var j=0; j<aNum.length; j++) { numHex += (aNum[j]+aNum[j]); } return numHex; } }else{ return that; } }; } // 16进制颜色转为RGB格式 if (typeof String.prototype.hexToRgb != "function") { String.prototype.hexToRgb = function() { var sColor = this.toLowerCase(); if (sColor && reg.test(sColor)) { if (sColor.length === 4) { var sColorNew = "#"; for (var i = 1; i < 4; i++) { sColorNew += sColor.slice(i,i+1).concat(sColor.slice(i,i+1)); } sColor = sColorNew; } // 处理六位的颜色值 var sColorChange = []; for (var j=1; j<7; j+=2) { sColorChange.push(parseInt("0x"+sColor.slice(j,j+2))); } return "RGB(" + sColorChange.join(",") + ")"; }else{ return sColor; } }; } // 移除字符串首尾空白 if (typeof String.prototype.trim != "function") { String.prototype.trim = function() { return this.replace(/^\s+|\s+$/g, ""); }; } }());
Atas ialah kandungan terperinci 详解JS中Array对象扩展与String对象扩展的方法. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!