Compare two objects (the order is not important, only the keys and values)

March 3, 2023

Let’s write a function compareRobots, that takes 2 robots and returns true, if only all the characteristics of both are the same. (the order is not important, only the keys and values).

Notes:
each robot has its own unique serialNo (do not check it when comparing)
properties can’t have values of undefined and NaN.

  const charlie = { serialNo: 1, chipVer: 12 };
  const lordy = { serialNo: 2, chipVer: 12 };
  compareRobots(charlie, lordy); // true

  const paul = { serialNo: 3, chipVer: 15 };
  compareRobots(paul, charlie); // false

   const mike = { serialNo: 4, chipVer: 12, wheels: 1 };
   compareRobots(mike, charlie); // false

   const max = { serialNo: 5, engineVer: 12 };
   compareRobots(max, charlie); // false

   const steve = { serialNo: 6 };
   compareRobots(steve, charlie); // false`

I write a code but I don’t know how to ignore the serialNo of robots

const compareRobots = (robot1, robot2) => {
// write code here
const entries1 = Object.entries(robot1);
const entries2 = Object.entries(robot2);

if (entries1.length !== entries2.length) {
  return false;
};

for (let i = 0; i < entries1.length; i++) {
  if (entries1[i][0] !== entries2[i][0]) {
    return false;
  }

  if (entries1[i][1] !== entries2[i][1]) {
    return false;
  }
};

  return true;
};`

>Solution :

Using Object.keys() and a Set() to get all unique keys of the two objects, then I simply remove the ones I don’t want to compare ("serialNo")

function compareRobots(a, b) {
  // determine all unique keys
  const keys = new Set([].concat(Object.keys(a), Object.keys(b)));
  // ignore serialNo;
  keys.delete("serialNo");

  for (const k of keys)
    if (a[k] !== b[k]) return false;
  return true;
}

const charlie = { serialNo: 1, chipVer: 12 };
const lordy = { serialNo: 2, chipVer: 12 };
const paul = { serialNo: 3, chipVer: 15 };
const mike = { serialNo: 4, chipVer: 12, wheels: 1 };
const max = { serialNo: 5, engineVer: 12 };
const steve = { serialNo: 6 };

console.log({
  "charlie, lordy": compareRobots(charlie, lordy), // true
  "paul, charlie": compareRobots(paul, charlie), // false
  "mike, charlie": compareRobots(mike, charlie), // false
  "max, charlie": compareRobots(max, charlie), // false
  "steve, charlie": compareRobots(steve, charlie), // false`
});