index.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> </head> <body> <script src="lodash.js"></script> <script> // console.log(_.uniq([1,2,3,21,3,1,5,7,8,'a','A'],function(val) { // return typeof val === 'string' ? val.toLocaleLowerCase() : val; // })) // console.log(_([1,2,3,21,3,1,5,7,8,'a','A']).uniq(function(val) { // return typeof val === 'string' ? val.toLocaleLowerCase() : val; // })) console.log(_.chain([1,2,3,21,3,1,5,7,8]).uniq().reduce().value()) </script> </body> </html>
lodash.js
(function(root){ var _ = function(obj) { if(!(this instanceof _)) { return new _(obj); } this.wrap = obj; } _.reduce = function(obj) { var result = 0; for(var i=0; i<obj.length; i++) { result += obj[i] } return result; } // 数组去重 _.uniq = function(target,callback) { var result = []; var computed; for(var i=0; i<target.length; i++) { computed = callback ? callback(target[i]) : target[i]; if(result.indexOf(computed) === -1) { result.push(computed) } } return result; } // 开启连接式的调用 _.chain = function(obj) { var instence = _(obj); instence._chain = true; return instence; } // 终止连接式调用 _.prototype.value = function() { return this.wrap; } // 辅助函数 _.result = function(instence, obj) { return instence._chain ? _(obj).chain() : obj; } _.each = function(arr,callback) { for(var i=0; i<arr.length; i++) { callback.call(arr,arr[i]) } } _.functions = function(obj) { var result = []; for(var key in obj) { result.push(key); } return result; } // 自身拓展的方法 _.mixin = function(obj) { _.each(_.functions(obj),function(key) { var func = obj[key]; obj.prototype[key] = function() { var args = [this.wrap]; args = args.concat(arguments[0]) // args.push(arguments[0]) // Array.prototype.push.apply(args,arguments) return _.result(this, func.apply(this, args)); } }) } _.mixin(_); root._ = _; })(this)