CODEWITHSUNDEEP
javascript
Deke
Deke

Reputation: 4649

How to check if two objects properties match?

Lets say there are two objects but one object has property different from the other. Is there a way to figure out what properties match?

for example:

var objectOne = {
  boy: "jack",
  girl: "jill"
}


var objectTwo = {
  boy: "john",
  girl: "mary",
  dog: "mo"
}

edit: It should tell me boy and girl property name are found in both the objects.

Upvotes: 0

Views: 2872

Answers (6)

Julien
Julien

Reputation: 5729

This isn't better than some solutions here, but I thought I'd share:

function objectHas(obj, predicate) {
  return JSON.stringify(obj) === JSON.stringify({ ...obj, ...predicate })
}

Upvotes: 0

Joe Karlsson
Joe Karlsson

Reputation: 38

If you want to find out which keys match given two objects, you could loop through all of the keys of the objects using a for... in loop. In my function, it will loop through the keys and return an array of all of the matching keys in the two objects.

let objectOne = {
  boy: "jack",
  girl: "jill"
}

let objectTwo = {
  boy: "john",
  girl: "mary",
  dog: "mo"
}

function matchingKeys (obj1, obj2) {
  let matches = [];
  let key1, key2;
  
  for (key1 in obj1) {
    for (key2 in obj2) {
      if ( key1 === key2) {
        matches.push(key1);
      }
    }
  }
  return matches
}

const result = matchingKeys(objectOne, objectTwo);
console.log(result)

Upvotes: 1

Travis
Travis

Reputation: 83

Try this on for size:

function compare(obj1, obj2) {
    // get the list of keys for the first object
    var keys = Object.keys(obj1);

    var result = [];

    // check all from the keys in the first object
    // if it exists in the second object, add it to the result
    for (var i = 0; i < keys.length; i++) {
        if (keys[i] in obj2) {
            result.push([keys[i]])
        }           
    }

    return result;
}

Upvotes: 0

sbedulin
sbedulin

Reputation: 4342

Using Object.keys

Object.keys(objectOne).filter(k => Object.hasOwnProperty.call(objectTwo, k))

Upvotes: 2

Kijewski
Kijewski

Reputation: 26022

var in_both = [];
for (var key in objectOne) { // simply iterate over the keys in the first object
    if (Object.hasOwnProperty.call(objectTwo, key)) { // and check if the key is in the other object, too
        in_both.push(key);
    }
}

C.f. https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/hasOwnProperty

Now, if you want to test if the values are the same, too, than simply add more code to the condition/body of the inner if.

Upvotes: 3

kukkuz
kukkuz

Reputation: 42352

You can use Object.keys and use Array.prototype.reduce to loop through once and list out the common keys - see demo below:

var objectOne={boy:"jack",girl:"jill"};
var objectTwo={boy:"john",girl:"mary",dog:"mo"};

var result = Object.keys(objectOne).reduce(function(p,c){
  if(c in objectTwo)
    p.push(c);
  return p;
},[]);

console.log(result);

Upvotes: 1

Related Questions