Value won't print

This is the solution. But according to this solution, in the first if statement, the second or condition translates to obj[first] in the first example which translate to the value of the first property. But when I try let person = { first: "Romeo", last: "Montague" }; console.log(person[first]); in a code editor I get an error.

function whatIsInAName(collection, source) {
  // "What's in a name? that which we call a rose
  // By any other name would smell as sweet.”
  // -- by William Shakespeare, Romeo and Juliet
  var srcKeys = Object.keys(source);

  // filter the collection
  return collection.filter(function(obj) {
    for (var i = 0; i < srcKeys.length; i++) {
      if (
        !obj.hasOwnProperty(srcKeys[i]) ||
        obj[srcKeys[i]] !== source[srcKeys[i]]
      ) {
        return false;
    return true;

This tells Javascript to access the property of person with the string stored in the variable first

Right so it should print out β€œRomeo” correct?

no, because first is not a string, it is a variable name that has yet to be defined.

To access the first property of the object person, person['first'] would be correct.

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Ah so the reason this works in the solution is because the .keys() method is storing an array of strings. So obj[srcKeys[i]] equates to obj["first"] in the first example right?


Exactly right. srcKeys is an array of string values, each string being one of three property names on the src object. srcKeys[0] is one of those property names, might be "first" or might not. There is no hard rule about how property names get ordered when pulled by Object.keys()

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