Get the key when the value is an array-CodePudding

function getObjKey(obj, value) {
  return Object.keys(obj).find(key => obj[key] === value);
}

const obj = {city1: ['Santiago','Germany'], city2: 'Chicago'};

console.log(getObjKey(obj, ['Santiago','Germany']));

I want to get the key of ['Santiago','Germany'] this array value as city1

console.log(getObjKey(obj, 'Chicago'));

When I try the above code, I am getting the key of 'Chicago' as city2.

Same way I want to get the key of ['Santiago','Germany'] as well. How can I do that?

Any suggestions?

CodePudding user response：

You can use JSON.stringify.

Example:

function getObjKey(obj, value) {
  return Object.keys(obj).find(key => Array.isArray(obj[key]) ? JSON.stringify(obj[key]) === JSON.stringify(value) : obj[key] === value) ;
}

const obj = {city1: ['Santiago','Germany'], city2: 'Chicago'};

console.log(getObjKey(obj, 'Chicago'));

console.log(getObjKey(obj, ['Santiago','Germany']));

Output:

city2

city1

CodePudding user response：

You can use Object.entries(),
check if the value is an array or not and Check if the value exists like so:

function getObjKey(obj, value) {
  return Object.entries(obj).find(([k, v]) => {
    if(Array.isArray(v)) {
      return v.every(item => value.includes(item));
    } 
    
    return v === value;
  })?.[0];
}

const obj = {city1: ['Santiago','Germany'], city2: 'Chicago'};

console.log(getObjKey(obj, ['Santiago','Germany']));
console.log(getObjKey(obj, 'Chicago'));

CodePudding user response：

You need to check whether obj[key] is an Array or not if Array then use every to check it matches with all values and if it's not just check obj[key]===value

const getObjKey = (obj, value) => {

  return Object.keys(obj).find(key => {
    const currVal = obj[key];

    return Array.isArray(currVal) && Array.isArray(value) && currVal.length === value.length ? value.every(val => currVal.includes(val)) : currVal === value
  });
}

const obj = {
  city1: ['Santiago', 'Germany'],
  city2: 'Chicago',
  city3: 'Berlin'
};

console.log(getObjKey(obj, ['Santiago', 'Germany']));
console.log(getObjKey(obj, 'Chicago'));
console.log(getObjKey(obj, ['Santiago', 'Germany', 'Erlangen']));
console.log(getObjKey(obj, ['Berlin']));

CodePudding user response：

You can't compare arrays with === , a temporary solution can be parse the values as strings and then check if they are equal:

function getObjKey(obj, value) {
  return Object.keys(obj).find(key => JSON.stringify(obj[key]) === JSON.stringify(value));
}

But as I said, this should be a temporary solution since it would be slow for larger objects.