使用Node.js从其他js文件引用构造函数

Question

//default.js
const item = require("./item.js");
var itemTest = new item.ItemTest("weapon",1,1,1);
console.log(itemTest.name);

//item.js

module.exports = class ItemTest {
    constructor(name, value, attack, defense) {
        this.name = name;
        this.value = value;
        this.attack = attack;
        this.defense = defense;
    }

}

我也尝试过

 //item.js
    function ItemTest(name, value, attack, defense) {
        this.name = name;
        this.value = value;
        this.attack = attack;
        this.defense = defense;
    }

但这还会返回“ item.ItemTest不是构造函数”。 如果将该函数添加到default.js中，那么它将正常工作，但是我不知道如何使其从另一个文件中提取构造函数对象。

Answer 1

我通过替换这些行const item = require("./item.js");对您现有的代码进行了少量更改const item = require("./item.js"); 和var itemTest = new item.ItemTest("weapon",1,1,1); 这些const ItemTest = require("./item"); 和var itemTest = new ItemTest("weapon", 1, 1, 1);

//default.js
const ItemTest = require("./item");
var itemTest = new ItemTest("weapon", 1, 1, 1);
console.log(itemTest.name);

//item.js
class ItemTest {
    constructor(name, value, attack, defense) {
        this.name = name;
        this.value = value;
        this.attack = attack;
        this.defense = defense;
    }

}

module.exports = ItemTest;

在上面的代码中，我正在导出ItemTest因此在使用require()时可以访问它。 在需要文件时，您将导出类。

Answer 2

在Item.js中，您需要进行更改

 class ItemTest { constructor(name, value, attack, defense) { this.name = name; this.value = value; this.attack = attack; this.defense = defense; } } class MyClass {} // If you want to export more stuff, do module.exports = {ItemTest: ItemTest, MyClass: MyClass}; // But if you have only ItemTest, then you can do module.exports = ItemTest; // This will change the main code to be like var ItemTest = require('./item'); var itemTest = new ItemTest();