Question

我将player指定为一个对象，其中包含weapon等属性，这些属性是我定义为stick项的对象，它会附加一个值这可能是伤害。但是，当函数player.weapon.stick调用它时，它将返回错误“Uncaught TypeError：无法读取未定义的属性'棒'”。我相信它说武器是未定义的，但是我定义所有这些的块是

//Player Data
var player = {
weapon: stick,
speed: 3,
armor: cloth,
location: pLocation
}
var pLocation = [tickX, tickY];

//Items
var stick = { stick: 1 };
var cloth = { ClothArmor: 1 };

问题在于我的定义或我如何称呼它player.weapon.stick

Answer 1

当您声明cloth时，应该定义

stick和player，因为它们尚未定义，但其值已解析为undefined且不会更改稍后当你定义它们时。

Answer 2

最好在使用之前定义变量

var pLocation = [tickX, tickY];

//Items
var stick = { stick: 1 };
var cloth = { ClothArmor: 1 };

//Player Data
var player = {
    weapon: stick,
    speed: 3,
    armor: cloth,
    location: pLocation
}

Answer 3

JS只提升功能 - 而不是变量。因此，您必须在使用它们之前定义变量。

var pLocation = [tickX, tickY];

    //Items
    var stick = { stick: 1 };
    var cloth = { ClothArmor: 1 };

    //Player Data
    var player = {
    weapon: stick,
    speed: 3,
    armor: cloth,
    location: pLocation
    }

或

var stick

//Player Data
var player = {
weapon: stick,
speed: 3,
armor: cloth,
location: pLocation
}
var pLocation = [tickX, tickY];

//Items
stick = { stick: 1 };
var cloth = { ClothArmor: 1 };

Answer 4

这里有几个问题，最重要的一个问题就是你似乎不理解对象（不是试图粗鲁，但是你还在使用它们是错误的）。

var pLocation = [tickX, tickY]; // place this first to avoid undefined location
var player = {
weapon: stick, // stick without quotation marks is a variable, not a string, so this would be player.weapon = stick where stick = undefined variable.
speed: 3,
armor: cloth,
location: pLocation // since pLocation is defined after in your script i currently has no value, so location will be undefined.
}
//alternatively for pLocation
player.location = [tickX, tickY];

//Items
var stick = { stick: 1 }; // this creates an object called stick with a variable called stick with the value 1, so stick.stick = 1.
var cloth = { ClothArmor: 1 }; // this creates an object called cloth with a variable called ClothArmor with the value 1, so cloth.ClothArmor = 1.

因此，如果你调用player.weapon.stick它是不正确的，因为武器不是一个对象，它是一个对象内部的变量。如果你想要player.weapon.stick你必须使用：

player = {
    weapon: {
        stick: 'Variable value'
    }
}

定义为对象的对象返回undefined

4 个答案: