JavaScript继承

对象冒充

function Person(name,age){
    this.name=name;
    this.setName=function(name){
        this.name=name;
    }
    this.getName=function(){
        return this.name;
    }
    this.getInfo=function(){
        alert("name:"+this.name);
    }
};
function Student(name,age){
    this.method=Person;
    this.method(name);
    delete this.method;
    this.age=age;
    this.setAge=function(age){
        this.age=age;
    }
    this.getAge=function(){
        return this.age;
    }
    this.getInfos=function(){
        alert("name:"+this.name+",age:"+this.age);
    }
}
var person=new Person("person");
var student=new Student("student",22);
person.getInfo();
student.getInfos();

call 方法方式

call 方法是 Function 对象中的方法，因此我们定义的每个函数都拥有该方法。可以通过函数名来调用 call 方法，call 方法的第一个参数会被传递给函数中的 this，从第 2 个参数开始，逐一赋值给函数中的参数。

function Person(name,age){
    this.name=name;
    this.setName=function(name){
        this.name=name;
    }
    this.getName=function(){
        return this.name;
    }
    this.getInfo=function(){
        alert("name:"+this.name);
    }
};
function Student(name,age){
    Person.call(this,name);
    this.age=age;
    this.setAge=function(age){
        this.age=age;
    }
    this.getAge=function(){
        return this.age;
    }
    this.getInfos=function(){
        alert("name:"+this.name+",age:"+this.age);
    }
}
var person=new Person("person");
var student=new Student("student",22);
person.getInfo();
student.getInfo();
student.getInfos();

apply 方法方式

function Person(name,age){
    this.name=name;
    this.setName=function(name){
        this.name=name;
    }
    this.getName=function(){
        return this.name;
    }
    this.getInfo=function(){
        alert("name:"+this.name);
    }
};
function Student(name,age){
    Person.apply(this,new Array(name));
    this.age=age;
    this.setAge=function(age){
        this.age=age;
    }
    this.getAge=function(){
        return this.age;
    }
    this.getInfos=function(){
        alert("name:"+this.name+",age:"+this.age);
    }
}
var person=new Person("person");
var student=new Student("student",22);
person.getInfo();
student.getInfo();
student.getInfos();

原型链方式（无法给构造函数传参数）

function Person(){}
Person.prototype.name="name";
Person.prototype.getInfo=function(){
    alert("name:"+this.name);
}
function Student(){}
    Student.prototype=new Person();
    Student.prototype.age=0;
               
    Student.prototype.getInfos=function(){
        alert("name:"+this.name+",age:"+this.age);
    }
var person=new Person();
person.name="person";
var student=new Student();
student.name="student";
student.age=22;
person.getInfo();
student.getInfo();
student.getInfos();

混合方式（推荐）

function Person(name){
this.name=name;
}
Person.prototype.getInfo=function(){
alert("name:"+this.name);
}
function Student(name,age){
Person.call(this,name);
this.age=age;
}
Student.prototype=new Person();
Student.prototype.getInfos=function(){
alert("name:"+this.name+",age:"+this.age);
}
var person=new Person("person");
var student=new Student("student",22);
person.getInfo();
student.getInfo();
student.getInfos();