How to retrieve the key from an array of values of a JSON object?

Question

Let there is an object which has values as arrays. For example,

    const obj = {
      'abc': ['xyz','tuv'],
      'def': ['qrs']
    }

How can we get the key of 'tuv' from the object?

This is different from this question, where the value was not an array. How to get a key in a JavaScript object by its value?

Answer 1

You could get the keys and filter by checking the values.

 const getKeys = (object, value) => Object.keys(object).filter(k => object[k].includes(value)), obj = { abc: ['xyz','tuv'], def: ['qrs'] }; console.log(getKeys(obj, 'tuv'));

Answer 2

I am assuming one value will not have multiple keys.

const getKeyByValue = (object, value) => Object.keys(object)
  .map(key => object[key].map(val => { if (val === value) { return key }}))
  .flat().filter(key => key)[0] || false

So, if we want to get the key of 'tuv', we can call this method like this,

getKeyByValue(obj, 'tuv')