js find key in object code example

Example 1: how to find the key of an value in an object

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


const map = {"first" : "1", "second" : "2"};
console.log(getKeyByValue(map,"2"));

Example 2: js find key by value in object

Object.keys(object).find(key => object[key] === value)

Example 3: object keys javascript

const object1 = {
  a: 'somestring',
  b: 42,
  c: false
};

console.log(Object.keys(object1));
// expected output: Array ["a", "b", "c"]

Example 4: js check if object key exists

var obj = { key: undefined };
obj["key"] !== undefined // false, but the key exists!