从对象中删除空对象、数组、字符串或整数

Question

我有以下 sn-p 不起作用，并决定将其隔离到 nodejs 脚本中：

const _ = require('lodash');

let derpObject = {
    foo: "hey",
    bar: "",
    foo2: [],
    bar2: {}
}

function cleanObject(params) {
    const newObject = Object.keys(params).forEach( key => {
    console.log(params[key]);
        if(_.isNil(params[key]) || _.isEmpty(params[key])) {
      delete params[key]
    }
    });
  console.log('here', newObject);
  return newObject;
}

let result = cleanObject(derpObject);
console.log(result);

基本上，我的目的是检查主对象中哪些属性为空或 null 并删除它们，最后返回仅具有非空/null 属性的新对象。

但是，运行上面的脚本输出：

hey

[]
{}
here undefined
undefined
=> undefined

知道为什么我会变得不确定吗？我一直在用这个敲打我的头一段时间了

Answer 1

.forEach() 不返回任何内容因此undefined 输出，您可以尝试将值分配给新对象并避免更改原始对象：

function cleanObject(params) {
  const newObject = {};
  Object.keys(params).forEach(key => {
    //console.log(params[key]);
    if (!(_.isNil(params[key]) || _.isEmpty(params[key]))) {
        newObject[key] = params[key]
    }
  });
  //console.log('here', newObject);
  return newObject;
}

let derpObject = {
  foo: "hey",
  bar: "",
  foo2: [],
  bar2: {}
}

function cleanObject(params) {
  const newObject = {};
  Object.keys(params).forEach(key => {
    //console.log(params[key]);
    if (!(_.isNil(params[key]) || _.isEmpty(params[key]))) {
        newObject[key] = params[key]
    }
  });
  //console.log('here', newObject);
  return newObject;
}

let result = cleanObject(derpObject);
console.log(result);

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.15/lodash.min.js"></script>

---

纯lodash：

function cleanObject(params) {
  return _(params).omitBy(_.isNil).omitBy(_.isEmpty);
}

let derpObject = {
  foo: "hey",
  bar: "",
  foo2: [],
  bar2: {}
}

function cleanObject(params) {
  return _(params).omitBy(_.isNil).omitBy(_.isEmpty);
}

console.log(cleanObject(derpObject));

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.15/lodash.min.js"></script>

Answer 2

我想你快到了。我稍微更改了逻辑，以便在值有效时添加对象键和值（不为 nil 或不为空）

function cleanObject(params) {
    let newObject = {};
    Object.keys(params).forEach( key => {
        console.log(params[key]);
        if(!_.isNil(params[key]) || !_.isEmpty(params[key])) {
            newObject[key] = params[key]
        }
    });
  console.log('here', newObject);
  return newObject;
}

Answer 3

您可以将Array.prototype.reduce() 与Lodash#isNil() 和Lodash#isEmpty() 结合使用

代码：

const derpObject = {
  foo: "hey",
  bar: "",
  foo2: [],
  bar2: {}
}
const cleanObject = (o) => Object
  .keys(o)
  .reduce((a, k) => {
    if (!(_.isNil(o[k]) || _.isEmpty(o[k]))) {
      a[k] = o[k]
    }
    return a
  },{})
const result = cleanObject(derpObject)

console.log(result)

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.15/lodash.min.js"></script>