Compare Objects in JavaScript and Return Common Keys with Values

We are required to write a JavaScript function that takes in two objects. The function should return an array of all those common keys that have common values across both objects.

Example

The code for this will be −

const obj1 = { a: true, b: false, c: "foo" };
const obj2 = { a: false, b: false, c: "foo" };
const compareObjects = (obj1 = {}, obj2 = {}) => {
   const common = Object.keys(obj1).filter(key => {
      if(obj1[key] === obj2[key] && obj2.hasOwnProperty(key)){
         return true;
      };
      return false;
   });
   return common;
};
console.log(compareObjects(obj1, obj2));

Output

And the output in the console will be −

['b', 'c']