Algorithm_Wherefore art thou

I have been stuck in this algortihm for some hours. I wrote 5 or 6 solutions that didn’t work for every item. Now, I finally solved it, but I feel it’s a stupid solution… at least very unorthodox. Can you please take a look at it and help me to think in a better way?

I think the basic algorithms were pretty easy and very enjoyable. However, I am taking a long time to solve these intermediate algorithms and when I do, it always seems that it’s not the best way at all.

Thank you for your attention! This is my code…

function whatIsInAName(collection, source) {
  // What's in a name?
  var arr = [];
  // Only change code below this line
  var propSource = Object.keys(source);
  var test = 0;
  arr = collection.filter(function(obj) {
    for (i=0; i<propSource.length; i++) {
      if (obj.hasOwnProperty(propSource[i]) && obj[propSource[i]] === source[propSource[i]]) {
        test += 1;
      } else {
        test += 0;
      if (test === propSource.length) {
        test = 0;
        return true;
    test = 0;
  // Only change code above this line
  return arr;

whatIsInAName([{ first: "Romeo", last: "Montague" }, { first: "Mercutio", last: null }, { first: "Tybalt", last: "Capulet" }], { last: "Capulet" });

Is the same as
if (obj.hasOwnProperty(propSource[i]) && obj[propSource[i]] === source[propSource[i]]) {

Another solution would be just going with a for loop through the collection-array and test with for…in loop through source if collection has the property and if the value of that property is the same as in source.

You can also omit the .hasOwnProperty() call.

I think you can omit test = 0; before return true; since test is no longer used after the return.

Yes… I feel so stupid with this kind of stuff… :confused: I think I will have to study javascript better before continuing the remaining algorithms.
Thank you for your comments!

The .hasOwnProperty is really redundant. This one I have noticed by my own on other (failed) solutions I have came up with. Not on this specififc one… Thank you!

However, I can’t figure why if I omit the test = 0; before the return true; it doesn’t work for the second function call example:

whatIsInAName([{ "a": 1 }, { "a": 1 }, { "a": 1, "b": 2 }], { "a": 1 }) should return [{ "a": 1 }, { "a": 1 }, { "a": 1, "b": 2 }]

Any idea?

Ah! Because after the return the function stops and never resets the test variable, I think! :slight_smile: