如何检查对象内的动态属性的存在？

发布于 2025-01-19 09:37:26 字数 782 浏览 2 评论 0原文

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}
const result = {
    "MEN": [],
    "WOMEN": [],
    "CHILDREN TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

我有一个像上面这样的对象 result 。有时，它可能具有 KIDS TEMP 属性，有时可能具有 CHILDREN TEMP。由于此属性有空格，我无法使用点运算符来获取这些属性。如果 KIDS TEMP 或 CHILDREN TEMP 存在，我想创建一个标志。我尝试了以下方法：-

const part = 'KIDS TEMP' || 'CHILDREN TEMP';
    let check;
    if (result) {
      check = !!(result?.MEN.length !== 0 || result[part].length !== 0);
    }

但是当我收到 CHILDREN TEMP 说它无法读取未定义的长度时，上面的代码就中断了。我该如何解决这个问题？

原文

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}
const result = {
    "MEN": [],
    "WOMEN": [],
    "CHILDREN TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

I have an object result like above. Sometimes, it may have KIDS TEMP property and sometimes CHILDREN TEMP. Since this property has spaces, I cannot use dot operator to fetch these properties.
I want to create a flag if either of KIDS TEMP or CHILDREN TEMP exist.
I tried below:-

const part = 'KIDS TEMP' || 'CHILDREN TEMP';
    let check;
    if (result) {
      check = !!(result?.MEN.length !== 0 || result[part].length !== 0);
    }

But the above code breaks when I receive CHILDREN TEMP saying that it cannot read length of undefined.
How do I fix this?

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江心雾 2025-01-26 09:37:26

Object.keys() 返回对象的属性名称。你可以这样检查一个对象是否拥有某个属性：

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

console.log(Object.keys(result).includes("KIDS TEMP"));
console.log(Object.keys(result).includes("CHILDREN TEMP"));

如果你想测试某个属性是否存在，并且如果存在，则包含一个非空数组，你可以这样测试：

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

console.log(result["KIDS TEMP"]?.length > 0);
console.log(result["CHILDREN TEMP"]?.length > 0);

您的代码的主要问题是 const part = string1 || string2 始终计算为 string1，这不是您想要做的。

Object.keys() returns the property names of an object. You can check like this, if an object possesses a certain property:

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

console.log(Object.keys(result).includes("KIDS TEMP"));
console.log(Object.keys(result).includes("CHILDREN TEMP"));

If you want to test, if a certain attribute exists, and in case it exists, contains a non-empty array, you can test it like this:

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

console.log(result["KIDS TEMP"]?.length > 0);
console.log(result["CHILDREN TEMP"]?.length > 0);

The main problem with your code is that const part = string1 || string2 always evaluates to string1, which is not what you intend to do.

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靖瑶 2025-01-26 09:37:26

您可以使用对象的方法 hasOwnProperty它将返回 true/false 取决于属性是否存在于对象中。

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

console.log(result.hasOwnProperty('KIDS TEMP'),result.hasOwnProperty('CHILDREN TEMP'));

You can use Object's method hasOwnProperty it will return true/false depends on if property exists in object or not.

const result = {
    "MEN": [],
    "WOMEN": [],
    "KIDS TEMP": [
        "BCDEFHJJJJJJ34EEE234",
        "ABCDEFGHIJKL12345678"
    ]
}

console.log(result.hasOwnProperty('KIDS TEMP'),result.hasOwnProperty('CHILDREN TEMP'));

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