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Question

只有在javascript中创建对象的第一种方法是让我从中创建新对象。第二种和第三种创建对象的方式是抛出错误 谁能告诉我为什么会这样。让我知道我在代码中犯了什么错误。

'use strict'

// First Way for creating object
var log = function(){
    this.name = 'nitesh',
    this.lastName =  'Yadav',
    this.age =  '21'
}
Object.defineProperty(log,'name',{
    enumerable: false,
    writable: false,
    configurable: false
})
var for = new log(); ***// Works fine*** 
console.log(foo.name); // nitesh

// Second Way for creating object

var log2 = {
    name: 'nitesh',
    lastname: 'yadav',
    age: '21'
}
var foo2 = new log2; ***//Not working***
console.log(foo2.name) // Result error Why???

// third Way for creating object

var log3 = Object.create(Object.prototype,{
    name:{
        value: 'nitesh',
        enumerable: true,
        writable: true,
        configurable: true
    },
    age: {
        value: '21',
        enumerable: true,
        writable: true,
        configurable: true
    }
})

var foo3 = new log3; ***//Not working***
console.log(foo3.name) // Result error Why???

Answer 1

第一种情况是创建＆＃34; class＆＃34;而且你可以制作任意数量的物品。

在第二种和第三种情况下，您自己创建了对象，而您无法从对象创建对象。您可以在创建后立即使用它们：

// Second Way for creating object

var log2 = {
    name: 'nitesh',
    lastname: 'yadav',
    age: '21'
}
// var foo2 = new log2; // This line is not needed 
console.log(log2.name) // No Error

// third Way for creating object

var log3 = Object.create(Object.prototype,{
    name:{
        value: 'nitesh',
        enumerable: true,
        writable: true,
        configurable: true
    },
    age: {
        value: '21',
        enumerable: true,
        writable: true,
        configurable: true
    }
})

//var foo3 = new log3; // This line is not needed 
console.log(foo3.log3) // No Error