JS - How to get value from object by key

Question

I have an object called data like this:

var data = {
  operators: {
    operator1: {
      top: 20,
      left: 20,
      properties: {
        title: 'Operator 1',
        inputs: {},
        outputs: {
          output_1: {
            label: 'Output 1',
          },
          output_2: {
            label: 'Output 2',
          }
        }
      }
    },
    operator2: {
      top: 80,
      left: 300,
      properties: {
        title: 'Operator 2',
        inputs: {
          input_1: {
            label: 'Input 1',
          },
          input_2: {
            label: 'Input 2',
          },
          input_3: {
            label: 'Input 3',
          },
        },
        outputs: {}
      }
    },
  },
};

How to get a value from data by a key.

function myFunction(data, key) {
  //Find in data with key, and return value.
}

Result: var result = myFunction(data,'output_1') = Output 1 (get by Title).

Check the answer to this question: [Search recursively for value in object by property name](https://stackoverflow.com/questions/40603913/search-recursively-for-value-in-object-by-property-name) — Yosvel Quintero, Aug 30 '17 at 08:29
What do you mean by `get by Title` when you are passing a key to the function. — Muaaz Khalid, Aug 30 '17 at 08:32

score 1 · Answer 1 · edited Aug 30 '17 at 08:37

1

A simple solution could be:

function myFunction(data,key){
  if(data[key]){
    return data[key];
  }else{
    return myFunction(data[key],key);
  }
}

edited Aug 30 '17 at 08:37

Shubham

1,755
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answered Aug 30 '17 at 08:28

Jayyrus

12,961
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Nina Scholz · Accepted Answer · 2017-08-30T08:51:17.743

You could use an iterative and recursive approach and exit early if found.

The function getValue returns an object if found, otherwise it returnes false.

To get the value, you could take the property value.

function getValue(object, key) {
    var result;
    return Object.keys(object).some(function (k) {
        if (k === key) {
            result = { value: object[k] };
            return true;
        }
        if (object[k] && typeof object[k] === 'object' && (result = getValue(object[k], key))) {
            return true;
        }
    }) && result;    
}

var data = { operators: { operator1: { top: 20, left: 20, properties: { title: 'Operator 1', inputs: {}, outputs: { output_1: { label: 'Output 1' }, output_2: { label: 'Output 2' } } } }, operator2: { top: 80, left: 300, properties: { title: 'Operator 2', inputs: { input_1: { label: 'Input 1' }, input_2: { label: 'Input 2' }, input_3: { label: 'Input 3', foo: null } }, outputs: {} } } } };

console.log(getValue(data, 'output_1').value); // { label: 'Output 1' }
console.log(getValue(data, 'foo').value);      // null
console.log(getValue(data, 'bar'));            // false
console.log(getValue(data, 'bar').value);      // undefined

Can I get invert result? Ex: `Output 1` => `output_1` (`Output 1` is unique) — P. Pogba, Aug 30 '17 at 09:13
you mean, you want to search by value? just reverse check for `object[k] === value` and return the key instead of the value. — Nina Scholz, Aug 30 '17 at 09:16

JS - How to get value from object by key

2 Answers2