javascript get key from value 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: get keys of dictionary js

// Get keys of a dictionary
let dict = { a:1 , b:2 , c:3 }

console.log( Object.keys(dict) ) // expected output : ['a', 'b', 'c']

Example 3: javascript object entries

// Object Entries returns object as Array of [key,value] Array
const object1 = {
  a: 'somestring',
  b: 42
}
Object.entries(object1) // Array(2) [["a", "something"], ["b", 42]]
  .forEach(([key, value]) => console.log(`${key}: ${value}`))
// "a: somestring"
// "b: 42"

Example 4: javascript object get value by key

const person = {
  name: 'Bob',
  age: 47
}

Object.keys(person).forEach((key) => {
  console.log(person[key]); // 'Bob', 47
});