使用Lodash检查属性是否具有值

Question

我该如何检查任何value属性是否有值？

[
  {
    "name": "DESIGEMPRESA",
    "value": ""
  },
  {
    "name": "DSP_DIRECAO",
    "value": ""
  },
  {
    "name": "MES",
    "value": ""
  }
]

- Leonel Matias Domingos

Answer 1

你可以使用Array#some来检查是否存在至少一个元素没有空的value值。

var arr = [
  {
    "name": "DESIGEMPRESA",
    "value": ""
  },
  {
    "name": "DSP_DIRECAO",
    "value": ""
  },
  {
    "name": "MES",
    "value": ""
  }
],
res = arr.some(v => v.value != ''); //no object with not empty value

console.log(res);

- kind user

Answer 2

lodash中有一个函数叫做_.isEmpty()。

    const a = [
      {
        "name": "DESIGEMPRESA",
        "value": ""
      },
      {
        "name": "DSP_DIRECAO",
        "value": ""
      },
      {
        "name": "MES",
        "value": ""
      }
    ]
    
    const r = a.map(x => _.isEmpty(x.value))
    
    console.log(r)

<script src="https://cdn.jsdelivr.net/lodash/4.17.4/lodash.min.js"></script>

- Egor Stambakio

---

有点晚了，但我认为如果你想通过数组进行映射并使用此检查来显示单个属性，这是最好的选择。 - hellomello

Answer 3

您不需要使用lodash：

arr.some(obj => Boolean(obj.value))

- Adam Shone

Answer 4

var arr = [
  {
    "name": "DESIGEMPRESA",
    "value": ""
  },
  {
    "name": "DSP_DIRECAO",
    "value": ""
  },
  {
    "name": "MES",
    "value": "d"
  }
]

var out = arr.filter(function(obj){
  return obj.value
})

console.log(out)

- Rohith K P

---

如果所有元素都是空值怎么办？ - kind user

@Kinduser out.length 将会是0。 - Rohith K P

我敢打赌，OP想要返回true/false。 - kind user

Answer 5

你可以使用_.find(collection, [predicate=_.identity], [fromIndex=0])https://lodash.com/docs/4.17.4#find。

  let x = [
    {
      "name": "DESIGEMPRESA",
      "value": "tr"
    },
    {
      "name": "DSP_DIRECAO",
      "value": ""
    },
    {
      "name": "MES",
      "value": ""
    }
  ]

  _.find(x, (o) => o.value.length > 0);

返回 {name: "DESIGEMPRESA" , value: "tr"}。

https://runkit.com/csprance/5904f9fcad0c6400123abaa2

- Chris Sprance