[转]扩展js基础类的方法

	/**
		 * 扩展基础类
		 * 得到字符串的长度，包括中文和英文
		 **/
		String.prototype.charlen = function() {
			var arr = this.match(/[^\x00-\xff]/ig);
			return this.length + (arr == null ? 0 : arr.length);
		}

		/**
		 * 扩展基础类
		 * 格式化字符串${0} -> 参考printf %s
		 **/
		String.prototype.format = function() {
			var args = arguments;
			return this.replace(/\$\{(\d+)\}/g,              
				function(m, i){
					return args[i];
				});
		} 

		/**
		 * 扩展基础类
		 * 字符串首尾去空格
		 **/
		String.prototype.trim = function() {
			return this.replace(/(^\s*)|(\s*$)/g, "");
		}

		/**
		 * 扩展基础类
		 * 字符串包含字符串判断
		 **/
		String.prototype.contains = function(sub) {
			return this.indexOf(sub) != -1;
		}

		/**
		 * 扩展基础类
		 * 字符串比较大小
		 **/
		String.prototype.compare = function(b) {
			if(!b)
				return -1;

			if(this.length != b.length)
				return this.length - b.length;

			var i = 0;
			for (; i < this.length; i++){
				var val = this.charCodeAt(i) - b.charCodeAt(i);
				if(val != 0)
					return val;
			}

			return 0;
		}

		/**
		 * 扩展基础类
		 * 替换字符
		 **/
		String.prototype.replaceLen = function(start, len, replaced) {
			if(!len)
				return this;

			if(start >= this.length)
				return this;

			var returnSeg = '';
			var returnSeg2 = '';
			var i = 0;
			for (; i < this.length; i++){
				var c = this.charAt(i);
				if(i < start)
					returnSeg += c;

				if(i >= start + len)
					returnSeg2 += c;
			}

			return returnSeg + replaced + returnSeg2;
		}

		/**
		 * 扩展基础类
		 * 替换字符，这个在替换填入比较有用，比如***天***小时 替换为 <input />天<input />小时
		 **/
		String.prototype.replaceChar = function(target, replaced, start) {
			if(!target)
				return this;

			if(!start)
				start = 0;

			var returnVal = this.substring(0, start);
			var index = 0;
			for (var i = start; i < this.length; i++) {
				var c = this.charAt(i);
				target = typeof target == 'function' ? target.call(this, index) : target;
				if (c == target) {
					returnVal += typeof replaced == 'function' ? replaced.call(this, index) : replaced;
					while (i < this.length - 1 && this.charAt(i + 1) == c) {
						i++;
					}
					index++;
				}else{
					returnVal += c;
				}
			}

			return returnVal;
		}

		/**
		 * 扩展基础类
		 * 克隆复制（简单copy而已）
		 **/
		Array.prototype.clone = function(){
			var arr = [];
			var i = 0;
			for(; i < this.length; i++){
				switch(typeof this[i]){
					case 'object':
						var obj = {};
						for(key in this[i])
							obj[key] = this[i][key];
						arr.push(obj);
						break;
					default:
						arr.push(this[i]);
						break;
				}
			}
			return arr;
		}

		/**
		 * 扩展基础类
		 * 清空
		 **/
		Array.prototype.clear = function() {
			this.splice(0, this.length);
		}

		/**
		 * 扩展基础类
		 * 数组包含元素
		 **/
		Array.prototype.contains = function(el) {
			var i;
			for(i = 0; i < this.length; i++) {  
				if(this[i] == el)  
					return true;  
			}  
			return false;  
		}

		/**
		 * 扩展基础类
		 * 数组添加数组
		 **/
		Array.prototype.merge = function(arr) {
			if(arr){
				var i;
				for(i = 0; i < arr.length; i++) {  
					this.push(arr[i]);
				}  
			}
		}

		/**
		 * 扩展基础类
		 * 根据值和属性获取到数组的对象下标
		 **/
		Array.prototype.indexOf = function(val, field){
			var i = 0;
			for(; i < this.length; i++){
				if(this[i] && (field ? this[i][field] == val : this[i] == val)){
					return i;
				}
			}
			return -1;
		}

		/**
		 * 扩展基础类
		 * 最后一个下标
		 **/
		Array.prototype.lastIndexOf = function(val, field){
			var i = 0;
			var max = -1;
			for(; i < this.length; i++){
				if(this[i] && (field ? this[i][field] == val : this[i] == val)){
					max = i;
				}
			}
			return max;
		}

		/**
		 * 扩展基础类
		 * 数组唯一
		 **/
		Array.prototype.unique = function(field){
			var arr = [];

			var i = 0;
			for(; i < this.length; i++){
				var val = field ? this[i][field] : this[i];
				var index = this.lastIndexOf(val, field);
				if(index == i)
					arr.push(this[i]);
			}

			return arr;
		}

		/**
		 * 扩展基础类
		 * 数组最大值
		 **/
		Array.prototype.max = function(field){
			var result = -1;

			var i = 0;
			for(; i < this.length; i++){
				var val = field ? this[i][field] : this[i];
				if(val > result)
					result = val;
			}

			return result;
		}

		/**
		 * 扩展基础类
		 * 数组最小值
		 **/
		Array.prototype.min = function(field){
			var result = -1;

			var i = 0;
			for(; i < this.length; i++){
				var val = field ? this[i][field] : this[i];
				if(val < result)
					result = val;
			}

			return result;
		}

		/**
		 * 扩展基础类
		 * 日期格式化
		 **/
		Date.prototype.format = function(pat){
			var year = this.getFullYear();
			var month = this.getMonth() + 1;
			var day = this.getDate();
			var hour = this.getHours();
			var minute = this.getMinutes();
			var second = this.getSeconds();
			// 两位补齐
			month = month > 9 ? month : "0" + month;
			day = day > 9 ? day : "0" + day;
			hour = hour > 9 ? hour : "0" + hour;
			minute = minute > 9 ? minute : "0" + minute;
			second = second > 9 ? second : "0" + second;
			if(!pat){
				pat = "yyyy-MM-dd";
			}
			pat = pat.replace(/yyyy/g, year);
			pat = pat.replace(/MM/g, month);
			pat = pat.replace(/dd/g, day);
			pat = pat.replace(/HH/gi, hour);
			pat = pat.replace(/mm/g, minute);
			pat = pat.replace(/ss/g, second);
			return pat;
		}

		// 减去时差的毫秒数（取决于使用的浏览器的locale设置）
		Date.prototype.getTime2 = function(){
//			return this.getTime();
			return this.getTime() - this.getTimezoneOffset() / 60 * 3600 * 1000;
		}

		// 日期相差天数
		Date.prototype.diff = function(date){
			return Math.ceil((this - date) / (1000 * 60 * 60 * 24));
		}

		// 日期加减计算
		Date.prototype.add = function(days){
			return new Date(this.getTime() + days * (1000 * 60 * 60 * 24));
		}

		// 日期加减计算
		Date.prototype.addMonth = function(months){
			var day = this.getDate();
			var month = this.getMonth() + 1;
			var year = this.getFullYear();
			month += months;  
			if(month > 12){
				year += Math.floor(month / 12);
				month = month % 12;
			}
			return Date.parse(month + '/' + day + '/' + year);
		}

		// 解析字符串，以默认 pat = "yyyy-MM-dd"的格式，而不是MM/dd/yyyy
		Date.parse2 = function(str, pat){
			if(str == null || str == '')
				return new Date();
			var rstr = str.replace(/(\d{4})([-\./])(\d{1,2})\2(\d{1,2})/, "$3/$4/$1");
			return new Date(Date.parse(rstr));
		}

		// 解析字符串，json date obj
		// 减去时差的毫秒数（取决于使用的浏览器的locale设置）
		Date.parse3 = function(obj){
//			return new Date(obj.time);
			return new Date(obj.time - new Date().getTimezoneOffset() / 60 * 3600 * 1000);
//			var str = obj.year + '-' + (obj.month + 1) + '-' + obj.date + ' ' + 
//				obj.hours + ':' + obj.minutes + ':' + obj.seconds;
//			return Date.parse2(str);
		}