1 //用add方法替换sub方法
2 function add(a,b){
3 console.log(a+b)
4 }
5 function sub(a,b){
6 console.log(a-b)
7 }
8 add.call(sub,3,1);
9
10 //c1的方法放到c2上执行
11 function Class1(){
12 this.cName = 'class1';
13 this.showClass = function(){
14 console.log(this.cName)
15 }
16 }
17 function Class2(){
18 this.cName = 'class2';
19 }
20 var c1 = new Class1();
21 var c2 = new Class2();
22 c1.showClass.call(c2);
23
24 //实现继承 用Class3对象代替Class4的this对象,Class4即拥有所有Class3的属性和方法
25 function Class3(){
26 this.showTxt = function(txt){
27 console.log(txt)
28 }
29 }
30 function Class4(){
31 Class3.call(this)
32 }
33 var c4 = new Class4();
34 c4.showTxt('hello');
35
36 //多重继承
37 function Add() {
38 this.showAdd = function(a, b) {
39 console.log(a+b)
40 }
41 }
42 function Sub() {
43 this.showSub = function(a, b) {
44 console.log(a-b)
45 }
46 }
47 function Count(){
48 Add.call(this);
49 Sub.call(this);
50 }
51 var c = new Count();
52 c.showAdd(1,3);
53 c.showSub(1,3);
