How to check if a key is empty or not in an array of objects?

Question

I am doing react native application. And I am getting json response like below.

[
  {
    id: '508',
    class: 'class1',
    value: '0',
    percentage: '8.90',
    color: 'black'
  },
  {
    id: '509',
    class: 'class2',
    value: '0',
    percentage: '2.40',
    color: 'black'
  },
  {
    id: '510',
    class: 'class3',
    value: '0',
    percentage: '56.40',
    color: 'black'
  },
  {
    id: '511',
    class: 'class',
    value: '0',
    percentage: '2.40',
    color: 'black'
  }
]

I have to check all the value properties are empty or not. If all are empty, I have to do some action else condition other action.

  const emptyValues = sortedData.map(value => value.key);
  console.log('emptyValues data', emptyValues);

Note: I'm aware linked question checks for `null` and this post asks for empty values. However, the logic is same and approaches defined addresses solution for it — Rajesh, Mar 28 '19 at 09:25

Ori Drori · Accepted Answer · 2019-03-28T09:19:22.640

5

Use Array.every() to check if all value keys are '0' (or whatever your definition of empty is):

const data = [{"id":"508","class":"class1","value":"0","percentage":"8.90","color":"black"},{"id":"509","class":"class2","value":"0","percentage":"2.40","color":"black"},{"id":"510","class":"class3","value":"0","percentage":"56.40","color":"black"},{"id":"511","class":"class","value":"0","percentage":"2.40","color":"black"}]

const doEmptyAction = data.every(o => o.value === '0')

console.log(doEmptyAction)

edited Mar 28 '19 at 09:19

answered Mar 28 '19 at 09:04

Ori Drori

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My suggestion would be to have callback as `o => isEmpty(o.value)` and have a custom `isEmpty` function which would look like `isEmpty = (value) => value === undefined || value === null || value === ''`. We can also check for empty objects/arrays in it. So OP has do define their empty criteria – Rajesh Mar 28 '19 at 09:29
Will this returns true or false? And this will check all the indexes, right? – Anilkumar iOS - ReactNative Mar 28 '19 at 09:46
But, Its always returning false? even the values are 0 – Anilkumar iOS - ReactNative Mar 28 '19 at 09:49
What is your definition of empty? – Ori Drori Mar 28 '19 at 09:51
I got it, Thank you. – Anilkumar iOS - ReactNative Mar 28 '19 at 09:52
It will check entire loop of data, right? – Anilkumar iOS - ReactNative Mar 28 '19 at 09:52
1

Yes it will, but if it finds a non empty value, and will stop and return `false`. Ready the documentation of every in the link. – Ori Drori Mar 28 '19 at 09:55
if i want to check if any property is empty or now but I got false! although it's not empty – Oliver D Sep 27 '20 at 21:49
@OliverD - create a new question with the data, what you tried, and the expected result. – Ori Drori Sep 27 '20 at 21:55
@OriDrori [here's](https://stackoverflow.com/questions/64093759/how-to-check-items-in-an-array-of-objects-is-empty-or-not-using-every) – Oliver D Sep 27 '20 at 22:07

score -1 · Answer 2 · answered Mar 28 '19 at 09:17

let arr = [
  {
    id: '508',
    class: 'class1',
    value: '0',
    percentage: '8.90',
    color: 'black'
  },
  {
    id: '509',
    class: 'class2',
    value: '0',
    percentage: '2.40',
    color: 'black'
  },
  {
    id: '510',
    class: 'class3',
    value: '0',
    percentage: '56.40',
    color: 'black'
  },
  {
    id: '511',
    class: 'class',
    value: '0',
    percentage: '2.40',
    color: 'black'
  }
];

let desiredVal = arr.map((obj) => {
   if(obj.value){
      //do something
   }
});

Just a general suggestion, an answer is incomplete without explanation. — Rajesh, Mar 28 '19 at 09:30

How to check if a key is empty or not in an array of objects?

2 Answers2