alg04-whereforeArtThou.js

/*
Source: <https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/wherefore-art-thou>

Wherefore art thou
Make a function that looks through an array of objects (first argument) and returns an array of all objects that have matching name and value pairs (second argument). Each name and value pair of the source object has to be present in the object from the collection if it is to be included in the returned array.

For example, if the first argument is [{ first: "Romeo", last: "Montague" }, { first: "Mercutio", last: null }, { first: "Tybalt", last: "Capulet" }], and the second argument is { last: "Capulet" }, then you must return the third object from the array (the first argument), because it contains the name and its value, that was passed on as the second argument.
*/
function myWhatIsInAName(collection, source) {
  var arr = [];
  // Only change code below this line

  // Only change code above this line
  return arr;
}

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

myWhatIsInAName([{ "apple": 1, "bat": 2 }, { "bat": 2 }, { "apple": 1, "bat": 2, "cookie": 2 }], { "apple": 1, "bat": 2 });
/*
Get a help > Get a hint <https://forum.freecodecamp.org/t/freecodecamp-challenge-guide-wherefore-art-thou/16092>
*/
//Solution 1
function whatIsInAName1(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;
  });
}

//Solution 2
function whatIsInAName2(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);

  return collection.filter(function(obj) {
    return srcKeys.every(function(key) {
      return obj.hasOwnProperty(key) && obj[key] === source[key];
    });
  });
}

//Solution 3
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) {
    return srcKeys
      .map(function(key) {
        return obj.hasOwnProperty(key) && obj[key] === source[key];
      })
      .reduce(function(a, b) {
        return a && b;
      });
  });
}