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.
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.
objectTwo.hasOwnProperty(key)? How does .call() help? (Interesting choice to link to the German documentation.)
objectTwo could have its own item hasOwnProperty. Not using .call is an easy attack vector, though it's unlikely to cause more than a DOS. Oops, did not notice that I linked the wrong language. You may simply edit the question next time.hasOwnProperty. But your way works for any object.Using Object.keys
Object.keys(objectOne).filter(k => Object.hasOwnProperty.call(objectTwo, k))
hasOwnProperty, because null and undefined might be valid values.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);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)
var, let, and undeclared-and-therefore-global variables.
key1 and key2 variables are still global, and - more importantly - your code doesn't actually run...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;
}
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 })
}
