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  • JavaScript函数与创建对象

    1.

    1. 通过new的方式创建对象,自己会返回一个对象

    function person(firstname, lastname, age, eyecolor) {
        this.firstname = firstname;
        this.lastname = lastname;
        this.age = age;
        this.eyecolor = eyecolor;
        //     return [this.firstname,this.lastname,this.age,this.eyecolor,this] 
    }
    ​
    var myFather = new person("John","Doe",50,"blue");
    var myFather2 = new person("John","Doe",50,"blue");
    var myMother = person("Sally", "Rally", 48, "green");
    console.log(myFather)
    console.log(typeof myFather)
    console.log(myMother)
    console.log(typeof myMother)
    console.log("----------")
     
     
     
     
    
    
     

    2. 函数带有返回值过后, new与执行函数都会返回一个数组

     
    function person(firstname, lastname, age, eyecolor) {
        this.firstname = firstname;
        this.lastname = lastname;
        this.age = age;
        this.eyecolor = eyecolor;
            return [this.firstname,this.lastname,this.age,this.eyecolor,this] 
    }
    ​
    var myFather = new person("John","Doe",50,"blue");
    var myFather2 = new person("John","Doe",50,"blue");
    var myMother = person("Sally", "Rally", 48, "green");
    console.log(myFather)
    console.log(typeof myFather)
    console.log(myMother)
    console.log(typeof myMother)
    console.log("----------")
     

     

    3. 在创建对象后,对象自己可以通过“实例名.xxx”添加,但是这个函数的其他对象无法得到新的属性。

    function person(firstname, lastname, age, eyecolor) {
        this.firstname = firstname;
        this.lastname = lastname;
        this.age = age;
        this.eyecolor = eyecolor;
    //         return [this.firstname,this.lastname,this.age,this.eyecolor,this] 
    }
    ​
    var myFather = new person("John","Doe",50,"blue");
    var myFather2 = new person("John","Doe",50,"blue");
    var myMother = person("Sally", "Rally", 48, "green");
    console.log(myFather)
    console.log(typeof myFather)
    console.log(myMother)
    console.log(typeof myMother)
    console.log("----------")
    ​
    myFather.dd = ()=>{
        console.log("ddddddd")
    }
    ​
    myFather.name = "new name"
    ​
    person.prototype.ff = function() {
        return console.log("fffff");
    }
    ​
    console.log(myFather.name)
    myFather.dd()
    //myFather2.dd()//报错
    myFather.ff()
    //myMother.ff()//报错
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  • 原文地址:https://www.cnblogs.com/sunupo/p/15539271.html
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