how to find a key in an object javascript code example

Example 1: how to check if object has key javascript

myObj.hasOwnProperty('key') // it checks object for particular key and not on prototype

Example 2: 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 3: js object contain key

if ('key' in myObj)
// better
if (!myObj.hasOwnProperty('key'))

Example 4: object keys javascript

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

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

Example 5: js find key by value in object

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