fcc_wherefore_art_thou.js

// FreeCodeCamp
// Intermediate Algorithm Scripting
// Wherefore Art Though

function whatIsInAName(collection, source) {
  // What's in a name?
  var keys = Object.keys(source);  
  return collection.filter(function(obj) {
    return keys.every(function(key) {
      return obj.hasOwnProperty(key) && obj[key] === source[key];
    });
  });
}

console.log(whatIsInAName([{ first: "Romeo", last: "Montague" }, { first: "Mercutio", last: null }, 
               { first: "Tybalt", last: "Capulet" }], { last: "Capulet" })); 
                // returns [{ first: "Tybalt", last: "Capulet" }]

console.log(whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 }));
              // returns [{ "a": 1, "b": 2 }, { "a": 1, "b": 2, "c": 2 }]