javascript创建函数的20种方式汇总

2019-11-20 12:11:39

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工作中常常会创建一个函数来解决一些需求问题，以下是个人在工作中总结出来的创建函数20种方式，你知道多少？

function sayHello(){    console.log('hello');}function leave(){    console.log('goodbye');}//testsayHello();

为完成需求，赶紧声明一个函数吧

 var sayHello = function(){    console.log('hello');}var leave = function(){    console.log('goodbye');}//testleave();

有求必应，函数表达数来解决

 var Action = {    sayHello : function(){        console.log('hello');    },    leave : function(){        console.log('goodbye');    }}//testAction.sayHello();

创建一个方法对象类看起来更整洁

 var Action = function(){};Action.sayHello = function(){    console.log('hello');}Action.leave = function(){    console.log('goodbye');}//testAction.sayHello();

为单体添加属性方法，净化命名空间

 var Action = function(){    return {        sayHello : function(){            console.log('hello');        },        leave : function(){            console.log('goodbye');        }    }}// //testvar a = Action();a.leave();

返回新对象我们还有更多的事情可以做

 var Action = function(){};Action.prototype.sayHello = function(){    console.log('hello');}Action.prototype.leave = function(){    console.log('goodbye');}//testvar a = new Action();a.sayHello();

原型链指向防止创建多次

 var Action = function(){};Action.prototype = {    sayHello : function(){        console.log('hello');    },    leave : function(){        console.log('goodbye');    }}//testvar a = new Action();a.leave();

对象赋给原型看上去更整洁

 var Action = function(){    this.sayHello = function(){        console.log('hello');    }    this.leave = function(){        console.log('goodbye');    }}//testvar a = new Action();a.leave();

别忘了还可以在类的内部添加属性

 Function.prototype.sayHello = function(){    console.log('hello');}Function.prototype.leave = function(){    console.log('leave');}//testvar f = function(){};f.sayHello();

基类原型拓展，新的一片空间

 Function.prototype.addMethod = function(name, fn){    this[name] = fn;}var methods = function(){};methods.addMethod('sayHello', function(){    console.log('hello');});methods.addMethod('leave', function(){    console.log('leave');});//testmethods.sayHello();

通用定义方法函数使用更方便

 Function.prototype.addMethod = function(name, fn){    this.prototype[name] = fn;}var Methods = function(){};Methods.addMethod('sayHello', function(){    console.log('hello');});Methods.addMethod('leave', function(){    console.log('leave');});//testvar a = new Methods();a.leave();

原形赋值我们还可以用类操作

Function.prototype.addMethod = function(name, fn){    this[name] = fn;    return this;}var methods = function(){};methods.addMethod('sayHello', function(){    console.log('hello');}).addMethod('leave', function(){    console.log('leave');});//testmethods.leave();

链式操作有何不可

 Function.prototype.addMethod = function(name, fn){    this.prototype[name] = fn;    return this;}var Methods = function(){};Methods.addMethod('sayHello', function(){    console.log('hello');}).addMethod('leave', function(){    console.log('leave');});//testvar a = new Methods();a.leave();

原型+链式=更进一步

 Function.prototype.addMethod = function(obj){    for(var key in obj){        this[key] = obj[key];    }}var methods = function(){};methods.addMethod({    sayHello : function(){        console.log('hello');    },    leave : function(){        console.log('goodbye');    }});//testmethods.leave();

添加对象一次做得更多

 Function.prototype.addMethod = function(obj){    for(var key in obj){        this.prototype[key] = obj[key];    }}var Methods = function(){};Methods.addMethod({    sayHello : function(){        console.log('hello');    },    leave : function(){        console.log('goodbye');    }});//testvar a = new Methods();a.leave();

原型有什么不可以

 Function.prototype.addMethod = function(obj){    for(var key in obj){        this[key] = obj[key];    }    return this;}var methods = function(){};methods.addMethod({    sayHello : function(){        console.log('hello');    }}).addMethod({    leave : function(){        console.log('goodbye');    }});//testmethods.leave();

函数式添加对象也可以链式操作

 Function.prototype.addMethod = function(obj){    for(var key in obj){        this.prototype[key] = obj[key];    }    return this;}var Methods = function(){};Methods.addMethod({    sayHello : function(){        console.log('hello');    }}).addMethod({    leave : function(){        console.log('goodbye');    }});//testvar a = new Methods();a.leave();

类的链式操作也可以做得更多

 Function.prototype.addMethod = function(){    if(arguments.length < 1)        return;    var tostring = Object.prototype.toString;    if(tostring.call(arguments[0]) === '[object Object]'){        for(var key in arguments[0]){            this[key] = arguments[0][key];        }    }else if(typeof arguments[0] === "string" && tostring.call(arguments[1]) === '[object Function]'){        this[arguments[0]] = arguments[1];    }    return this;}

函数添加封装一下

 Function.prototype.addMethod = function(){    if(arguments.length < 1)        return;    var tostring = Object.prototype.toString;    if(tostring.call(arguments[0]) === '[object Object]'){        for(var key in arguments[0]){            this.prototype[key] = arguments[0][key];        }    }else if(typeof arguments[0] === "string" && tostring.call(arguments[1]) === '[object Function]'){        this.prototype[arguments[0]] = arguments[1];    }    return this;}

类式添加追求的就是个性化

 Function.prototype.addMethod = function(){    if(arguments.length < 1)        return;    var cout = 0,        tostring = Object.prototype.toString,        that;    if(typeof arguments[0] === "boolean" && arguments[0]){        cout++;        that = this;    }else{        that = this.prototype;    }    if(tostring.call(arguments[cout]) === '[object Object]'){        for(var key in arguments[cout]){            that[key] = arguments[cout][key];        }    }else if(typeof arguments[cout] === "string" && tostring.call(arguments[cout + 1]) === '[object Function]'){        that[arguments[cout]] = arguments[cout + 1];    }    return this;}//textvar Text1 = function(){};Text1.addMethod('sayHello', function(){console.log('last say hello!')}).addMethod('leave', function(){console.log('last goodbye!')});var t = new Text1();t.sayHello();t.leave();var test2 = function(){};test2.addMethod(true, 'sayHello', function(){console.log('last say hello!')}).addMethod(true, 'leave', function(){console.log('last goodbye!')});test2.sayHello();test2.leave();

追求个性化，这么做不必说为什么

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