JS中call和apply函數(shù)用法實(shí)例分析

function animal(type,nickname){
 this.type = type;
 this.nickname = nickname;
 this.sayHello = function(){
 return 'hello';
 }
}
function cat(name,type,nickname){
 this.name = name;
 //cat繼承animal
 animal.call(this,type,nickname);
}
console.log(new cat('wsscat','cut','tom'));
/*
cat {
 name: 'wsscat',
 type: 'cut',
 nickname: 'tom',
 sayHello: [Function] }
*/

function animal(type,nickname){
 this.type = type;
 this.nickname = nickname;
 this.syaHello = function(){
 return 'hello';
 }
}
function cat(name,type,nickname){
 this.name = name;
 animal.apply(this,arguments);
}
console.log(new cat('wsscat','cut','tom'));
/*
cat {
 name: 'wsscat',
 type: 'wsscat',
 nickname: 'cut',
 syaHello: [Function] }
*/

function animal(type,nickname){
 this.type = type;
 this.nickname = nickname;
 this.syaHello = function(){
 return 'hello';
 }
}
function wscat(name,age){
 this.name = name;
 this.age = age;
 this.sayMe = function(){
 return 'my name:' + this.name + ', age:' + this.age;
 }
}
function cat(name,age,type,nickname){
 //第一種使用call
 animal.call(this,type,nickname);
 wscat.call(this,name,age);
 //第二種使用apply
 //animal.apply(this,[type,nickname]);
 //wscat.apply(this,[name,age]);
}
console.log(new cat('wscat',2,'cat','tom');
/*
cat {
 type: 'cat',
 nickname: 'tom',
 syaHello: [Function],
 name: 'wscat',
 age: 2,
 sayMe: [Function] }
*/

cat.prototype = new animal();

animal.call(this[,arg]);
//animal.apply(this[,argArray]);

function animal(type,nickname){
 this.type = type;
 this.nickname = nickname;
}
animal.prototype.sayHello = function(){
 return 'hello';
}
function wscat(name,age){
 this.name = name;
 this.age = age;
} 
//這里是關(guān)鍵，原型鏈只能單繼承，
//不能同時(shí)繼承多個(gè)原型鏈，所以要一級(jí)一級(jí)來。
wscat.prototype = new animal();
wscat.prototype.sayMe = function(){
 return 'my name:' + this.name + ', age:' + this.age;
}
function cat(name,age,type,nickname){
 animal.call(this,type,nickname);
 wscat.call(this,name,age);
}
cat.prototype = new wscat();
var obj = new cat('wscat',10,'cat','tom');
console.log(obj);
//animal { type: 'cat', nickname: 'tom', name: 'wscat', age: 10 }
console.log(obj.sayHello());//hello
console.log(obj.sayMe());
/*
 my name:wscat, age:10
*/