How to check an array inside json data is empty using jmespath?

Question

I have json data as below:

[
  {
    "id": "i_1",
    "name": "abc",
    "address": [
      {
        "city": [
          "city1",
          "city2"
        ]
      },
      {
        "city": [
          "city1",
          "city2"
        ]
      }
    ]
  },
  {
    "id": "i_2",
    "name": "def",
    "address": [
      {
        "city": []
      },
      {
        "city": []
      }
    ]
  }
]

Now, I want only that data where city array is not null. So in the above example the output should be 1st element i.e. with id i_1.

How to filter this json using jmespath library?

score 4 · Accepted Answer · answered Jan 28 '19 at 09:59

You can do this:

var arr = [
  {
    "id": "i_1",
    "name": "abc",
    "address": [
      {
        "city": [
          "city1",
          "city2"
        ]
      },
      {
        "city": [
          "city1",
          "city2"
        ]
      }
    ]
  },
  {
    "id": "i_2",
    "name": "def",
    "address": [
      {
        "city": []
      },
      {
        "city": []
      }
    ]
  }
];

console.log(jmespath.search(arr,"[?not_null(address[].city[])]"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/jmespath/0.15.0/jmespath.js"></script>

adiga · Answer 2 · 2019-01-28T08:40:45.033

0

You could do this in pure javascript using filter and every

const items=[{"id":"i_1","name":"abc","address":[{"city":["city1","city2"]},{"city":["city1","city2"]}]},{"id":"i_2","name":"def","address":[{"city":[]},{"city":[]}]}]

const filtered = items.filter(i => i.address.every(a => a.city && a.city.length > 0))

console.log(filtered)

This returns only if every object inside address has a non-empty city array.

edited Jan 28 '19 at 08:40

answered Jan 28 '19 at 08:32

adiga

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I want to do this using jmespath, is there any way to do this using jmespath? – Monarth Sarvaiya Jan 28 '19 at 08:35
1

you could simplify this a little by changing `a.city.length > 0` to just `a.city.length` – Nick Parsons Jan 28 '19 at 08:37
@MonarthSarvaiya I don't know, sorry. Just providing an alternative javascript solution. – adiga Jan 28 '19 at 08:43

Teocci · Answer 3 · 2019-01-28T09:55:12.403

You don't need to use jmespath library use filter and `every from the vanilla JS. It is more efficient.

let jsonTxt = '{"data":[{"id":"i_1","name":"abc","address":[{"city":["city1","city2"]},{"city":["city1","city2"]}]},{"id":"i_2","name":"def","address":[{"city":[]},{"city":[]}]}]}'

let jsonData = JSON.parse(jsonTxt);
let items = jsonData.data;
const result = items.filter(i => i.address.every(a => a.city && a.city.length))
console.log('id: ', result[0].id);
//using jmespath
console.log(jmespath.search({data: items}, "data[*].address[*].city"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/jmespath/0.15.0/jmespath.js"></script>

I am using other filters of jmespath, at this point I am stuck, so I want solution only using jmespath. Here is only some part of my code. — Monarth Sarvaiya, Jan 28 '19 at 09:02

How to check an array inside json data is empty using jmespath?

3 Answers3