Question

当我在console.log时，这段代码：

 var Student = function(name, address, gpa){

    console.log(this);
    this.name = name;
    this.address = address;
    this.gpa = gpa;

    console.log("name is equal to " + name);
    console.log("address is equal to " + address);
    console.log("gpa is equal to " + gpa);
};



    var studentCall = [
    new Student ({
        name: "Marshae Hannor",
        address:{
            street: "345 Main St",
            city: "Smyrna",
            state: "GA"},
        gpa: [2.5, 3.5, 4.0]}),
    new Student ({
        name: "Vernon Owens",
        address:{
            street: "439 Serious St",
            city: "Baltimore",
            state: "MD"},
        gpa: [3.5, 3.2, 3.7]})
];

这是我在console.log中获得的内容

Object {}
main2.js (line 39)
name is equal to [object Object]
main2.js (line 44)
address is equal to undefined
main2.js (line 45)
gpa is equal to undefined
main2.js (line 46)
Object {}
main2.js (line 39)
name is equal to [object Object]
main2.js (line 44)
address is equal to undefined
main2.js (line 45)
gpa is equal to undefined

有人可以帮我理解我做错了什么。感谢

Answer 1

在您对Student的调用中，您传递了一个单参数，该参数如下所示：

{
    name: "Marshae Hannor",
    address:{
        street: "345 Main St",
        city: "Smyrna",
        state: "GA"},
    gpa: [2.5, 3.5, 4.0]
}

但是你的Student函数希望得到三个离散的参数。所以你不用{和}来调用它而不给出参数的名称：

var studentCall = [
    new Student (
        "Marshae Hannor",
        {
            street: "345 Main St",
            city: "Smyrna",
            state: "GA"},
        [2.5, 3.5, 4.0]),
    new Student (
        "Vernon Owens",
        {
            street: "439 Serious St",
            city: "Baltimore",
            state: "MD"},
        [3.5, 3.2, 3.7])
];

或，修改Student以期望只接收包含这些属性的单个对象：

var Student = function(obj){

    console.log(this);
    this.name = obj.name;
    this.address = obj.address;
    this.gpa = obj.gpa;

    console.log("name is equal to " + this.name);
    console.log("address is equal to " + this.address);
    console.log("gpa is equal to " + this.gpa);
};

构造函数中的数组中的对象

1 个答案: