Find element in map

Question

I have a map of objects:

"0": {
    key: 'id',
    value: {
        name: "eval"
        // other variables
    }
},
"1": {
    key: 'id',
    value: {
        name: "help"
        // other variables
    }
} // and so on

I need to find an element in map that's name variable is eqaul to "eval". What's the easiest way to do this?

inb4: I am talking about maps, not objects https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map — don'tmindme, Dec 11 '21 at 21:29

score 2 · Answer 1 · answered Dec 11 '21 at 21:23

If "map" is an array

let arr = [{key:'id', value:{ name:'eval' }}]
let item = arr.find(el => el.value.name == 'eval')

If "map" is an object

let obj = {0:{key:'id', value:{ name:'eval' }}}
let item = Object.values(obj).find(el => el.value.name == 'eval')

Leau · Accepted Answer · 2021-12-11T21:39:36.747

1

Use <Array>.from to convert map values to array and after filter what you want.

const map = new Map();

map.set(0, {
  key: 'id',
    value: {
      name: "eval"
    }
});

map.set(1, {
  key: 'id',
    value: {
      name: "help"
    }
});

const result = Array.from(map.values())
  .filter(x => x.value.name === 'eval')[0];
  
console.log(result);

edited Dec 11 '21 at 21:39

answered Dec 11 '21 at 21:32

Leau

1,072
5
19

Maik Lowrey · Answer 3 · 2021-12-11T21:45:46.587

0

The good old forEach Loop can do it too.

const data = [{
    key: 'id',
    value: {
        name: "eval"
        // other variables
    }
},
{
    key: 'id',
    value: {
        name: "help"
        // other variables
    }
}]

let res = [];
data.forEach((el) => {
  if (el.value.name === "eval") {
    res.push(el);
  }  
})

console.log(res)

edited Dec 11 '21 at 21:45

answered Dec 11 '21 at 21:39

Maik Lowrey

15,957
6
40
79

score 0 · Answer 4 · answered Dec 11 '21 at 21:52

0

You can do this

const tmp = {
  "0": {
    key: "id",
    value: {
      name: "eval"
      // other variables
    }
  },
  "1": {
    key: "id",
    value: {
      name: "eval"
      // other variables
    }
  }
};

function findEval(obj, target) {
    const elem = Object.keys(obj).filter(key => tmp[key].value.name === target);
    return elem.map(e => obj[e]);
}
console.log(findEval(tmp, 'eval'))

but better use lodash Find property by name in a deep object

answered Dec 11 '21 at 21:52

Alexander Kosykh

361
1
3

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community Dec 12 '21 at 00:05

score 0 · Answer 5 · answered Dec 11 '21 at 23:57

simple and best solution

const tmp = {
  "0": {
    key: "id",
    value: {
      name: "eval"
      // other variables
    }
  },
  "1": {
    key: "id",
    value: {
      name: "eval"
      // other variables
    }
  }
};

function findEval(obj, target) {
    for (var i=0; i < Object.keys(obj).length; i++) {
        if (obj[i].value.name === target) {
            return obj[i].value.name;
        }
    }
}
console.log(findEval(tmp, 'eval'))

Find element in map

5 Answers5