Javascript - 如果所有属性都为null，则将Object设置为null [英] Javascript - Set Object null if all its properties are null

问题描述

我有一个这样的对象：

var user = {
    id: 101,
    email: '[e-mail]',
    personalInfo: {
        name: null,
        address: {
            line1: null,
            line2: null,
            city: null,
            state: null
        }
    }
}

我想迭代属性并检查它的属性是否为null。如果它们都为null我想将该属性设置为null。这意味着从其全部为null的地址开始，因此设置地址= null，然后名称和地址都为空，因此personalInfo应设置为null等...

I would like to iterate the properties and check if its properties are null. If they are all null I want to set that property null. This means starting from address whose values are all null so set address = null, then name and address are both null so personalInfo should be set null etc...

所以我的对象结束如下：

So my Object ends ups like this:

var user = {
    id: 101,
    email: '[e-mail]',
    personalInfo: null
}

推荐答案

您可以迭代所有键/​​值对并减少此级别的所有 null 值的计数。如果所有值都是 null ，则返回 null ，否则返回更改的对象。

You could iterate all key/value pairs and decrement a count for all null values for this level. If all values are null, return null, otherwise the changed object.

为了检查嵌套对象，取值和类型并再次调用函数并将结果分配给键。

For checking the nested objects, take the value and the type and call the function again and assign the result to the key.

function setNull(object) {
    var entries = Object.entries(object),
        count = entries.length;
    
    entries.forEach(([k, v]) => {
        if (null === (v && typeof v === 'object' && (object[k] = setNull(v)))) {
            count--;
        }
    });

    return count
        ? object
        : null;
}

var user = { id: 101, email: '[e-mail]', personalInfo: { name: null, address: { line1: null, line2: null, city: null, state: null } } };

console.log(setNull(user));

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