提问人：J.F. 提问时间：7/20/2023 最后编辑：RF1991J.F. 更新时间：7/20/2023 访问量：37
有没有办法在数组中调用“新”对象构造函数，这些构造函数都包含在一个对象中？
Is there a way to call a "new" object constructor inside of an array all housed in an object?
问：
如果将对象同时具有对象构造函数和数组，则会同时调用对象构造函数的“new”，从而出现一条错误消息，指出未定义对象构造函数名称。
这是我的 JavaScript 代码：
var game = {
//constructor function for every block type
blockType: function(name, imageX, imageY, width, height, xEffect, yEffect, passable) {
//name is just for reference
this.name = name;
this.imageX = imageX;
this.imageY = imageY;
this.width = width;
this.height = height;
this.xEffect = xEffect;
this.yEffect = yEffect;
//if collision would be on or off
this.passable = passable;
},
blockTypes: [new blockType("basicBlack", 0, 0, 50, 50, 0, 0, false)],
};
错误消息说
blockType 未定义
相反，当我放时，有错误消息，new game.blockType
游戏未定义
我是声明或称事情是错误的，还是有办法解决这个问题？
答：
2赞
trincot
7/20/2023
#1
new blockType引用具有该名称的变量，但没有此类变量。请注意，这是一个属性，而不是一个变量。game.blockType
new game.blockType在分配一个值之前进行计算，因此也无法正常工作。game
有很多解决方案。例如，首先定义不带第二个属性，然后添加它：game
var game = {
//constructor function for every block type
blockType: function(name, imageX, imageY, width, height, xEffect, yEffect, passable) {
//name is just for reference
this.name = name;
this.imageX = imageX;
this.imageY = imageY;
this.width = width;
this.height = height;
this.xEffect = xEffect;
this.yEffect = yEffect;
//if collision would be on or off
this.passable = passable;
},
};
game.blockTypes = [new game.blockType("basicBlack", 0, 0, 50, 50, 0, 0, false)];
console.log(game);另一种解决方案是首先创建为（局部）变量：blockType
var game = (() => {
//constructor function for every block type
const blockType = function(name, imageX, imageY, width, height, xEffect, yEffect, passable) {
//name is just for reference
this.name = name;
this.imageX = imageX;
this.imageY = imageY;
this.width = width;
this.height = height;
this.xEffect = xEffect;
this.yEffect = yEffect;
//if collision would be on or off
this.passable = passable;
};
const blockTypes = [new blockType("basicBlack", 0, 0, 50, 50, 0, 0, false)];
return {blockType, blockTypes};
})(); // Immediately invoked function expression
console.log(game);评论
0赞
J.F.
7/20/2023
谢谢。第一种方法很好地解决了我的问题。
评论
[new blockType(...在对象仍在定义时当场调用，因此尚未定义。您可以在定义对象后对其进行定义。