Is it possible to use LoDash _.filter to return values if you only know a key contains a certain string? So let's say you have the following data:

Mydata{
"banana" : "1"
}

And I want to return the values that contain "ana"? Everything I found on LoDash is mostly about searching the element values but not the keys.

Is it possible to use LoDash _.filter to return values if you only know a key contains a certain string? So let's say you have the following data:

Mydata{
"banana" : "1"
}

And I want to return the values that contain "ana"? Everything I found on LoDash is mostly about searching the element values but not the keys.

• javascript
• json
• lodash

3 Answers 3

If you want to get an array of the values, which keys conform to a criterion, Lodash's _.filter() works with objects as well. The 2nd param passed to the callback is the key.

var data = {
  "banana": 1,
  'lorem': 2,
  '123ana': 3
}

var result = _.filter(data, function(v, k) {
  return _.includes(k, 'ana');
});

console.log(result);

<script src="https://cdnjs.cloudflare./ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

If you want an object, which properties conform to a certain criterion, you can use _.pickBy() in a similar way.

var data = {
  "banana": 1,
  'lorem': 2,
  '123ana': 3
}

var result = _.pickBy(data, function(v, k) {
  return _.includes(k, 'ana');
});

console.log(result);

<script src="https://cdnjs.cloudflare./ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

You could reach desired result using native Array#reduce and return an object containing only these keys, which includes given string.

const obj = {
  banana: 'foo',
  hello: 'bar',
  foo: 'fzz',
  ana: 'xoo',
}

const check = (obj, str) => {
  return Object.keys(obj).reduce((s, a) => {
    if (a.includes(str)) {
      s[a] = obj[a];
    }
    return s;
  }, {});
}

console.log(check(obj, 'ana'));

You can first use filter() to get keys with specific part of string and then map() to get values.

var data = {
  "banana": 1,
  'lorem': 2,
  '123ana': 3
}

var result = _.chain(data)
  .keys()
  .filter(e => _.includes(e, 'ana'))
  .map(e => data[e])
  .value()
  
console.log(result)

<script src="https://cdnjs.cloudflare./ajax/libs/lodash.js/4.17.4/lodash.js"></script>