Implementation code of js inheritance_javascript skills-JS Tutorial-php.cn

base.js --implementation of inheritance ========================== [Note]: After inheritance, if the parent class is a class , it will inherit its properties, methods (including those declared with prototype), and static methods, otherwise only properties and methods will be inherited.

Copy code The code is as follows: Object.prototype.extendf= function (a,b) { if(!a||!b) return; var fa = typeof a=="function"; var fb = typeof b=="function"; var cha = function (a,b){ for(var c in b){ if(a[c]==undefined)//Subclass rewrite a[c]=b[c]; } return a; //Return the inherited object } if(fa&&fb){ b.apply(this,a.arguments); cha(a,b ); this["base"] =new b;//Access the parent class through base return cha(this,b.prototype); } else if(!fa&&fb){ cha(a,new b); a["base"]= new b; return cha(a,b); }else if(fa&&!fb){ cha (a,b); this["base"]=b; return cha(this,b); }else if(!fa&&!fb){ a["base" ]=b; return cha(a,b); } } Test page: Usage Copy code The code is as follows: var car2 = { name: "Car [parent category]", price: "Tens of thousands [parent category]", start : function( ){ alert(this.name " Started 2! [Parent Class]"); }, run : function(){ alert(this.name " Running 2. . . [Parent class]"); }, stop: function(){ alert(this.name "Stopped 2! [Parent class]"); }, remark: function(){return "[Parent class] 2 I am a car" this.name "; value" this.price;} // this.remark = "I am a car" this.name " ;The value of "this.price; } //car2.prototype.extra = function(ext){ // return this.name "The tariff 2 is: " ext; // } car2.protect = "[parent class] 2 protected"; car2.noExtra = function(){ return car.protect "No tariff 2 [parent class]"; } var car = function(name,price){ this.name=name||"Car [parent class]"; this.price=price||"Tens of thousands [parent class]" ; this.start = function(){ alert(this.name " Started! [parent class]"); }; this.run = function(){ alert(this.name " Driving... [parent class]"); }; this.stop= function(){ alert(this.name " Stopped! [parent class] ]"); }; this.remark = function(){return "[Parent class] I am a "this.name"; value" this.price;}; // this .remark = "I am a car" this.name ";value" this.price; //Note that if you do this, name and price will not get the passed parameters, so comment } car.prototype.extra = function(ext){ return this.name "The tariff is [parent class]:" ext; } car.protect = "[parent class] protected"; car. noExtra = function(){ return car.protect "No customs duties [parent class]"; } var BMW = function(){ this.extendf(BMW,car); this.name = "BMW [Subclass]"; this.start=function(){ alert(this.name "Exclusive starting device! "); }; return ("this.name1=" this.name); } var BMW2 = function(){ this.extendf(BMW2,car2); this.name = "BMW Ultimate No. 2 [Subcategory]"; this.start=function(){ alert(this.name "Exclusive starting device No. 2 Future!"); }; return ("this.name1=" this.name); } var bensi = { name:"bensi", price:"1.3 million", start:function(){ alert(this.name " Gorgeous start!"); }, stop:function(){ alert(this.name " Special brake to stop! "); } } bensi.noExtra=function(){ return "Who dares to collect taxes? "; } var autuo = { name:"autuo【subcategory】", price: "10,000", stop:function(){ alert( this.name "Alto is out of action!"); } } function ChangAn(){ this.extendf(ChangAn,car); // this.name = "CHANGAN [Subclass]"; this.run=function(){ alert(this.name " Going a little slow..."); } } var ftest = function(){ var tb = new BMW("BMW","700,000"); testRun(tb); alert(BMW.noExtra()); } var ftest2 = function(){ var tb = bensi//("Benz","1.2 million"); tb.extendf(bensi,car); testRun(bensi); alert(bensi.noExtra()); } var ftest3 = function(){ var tb = new ChangAn("Chang'an[Pass parameter]","50,000"); testRun (tb); alert(ChangAn.noExtra()); } var ftest4 = function(){ var tb = autuo tb.extendf(autuo,car2); testRun(tb); alert(autuo.noExtra()); } var ftest5 = function(){ var tb = autuo tb.extendf(autuo,bensi ); alert(tb.name); tb.start(); tb.stop(); alert(autuo.noExtra()); } var ftest6 = function(){ var tb = new BMW2("BMW 2","650,000"); var scar = document.getElementById("showcar"); scar.innerHTML = tb .remark(); alert(tb.name); tb.start(); tb.stop(); alert(BMW2.noExtra()); } //Test output function testRun(tb){ var scar = document.getElementById("showcar"); if(!scar) return false; scar.innerHTML = tb. remark(); tb.base.start(); tb.start(); tb.base.run(); tb.run(); tb.base .stop(); tb.stop(); alert(tb.extra("10,000")); //This will go wrong when the parent class is Object, because the parent class itself does not have } js test: ps: I haven’t noticed any performance issues, and I’d like to ask everyone to improve it. I want to use only one parameter, is there any way? Nested class I haven’t tried it yet.