Bonfire - Where art thou Solutions - FreeCodeCamp

FCC Bonfire - Where art thou Solutions.md

Many of the solutions available around the internet for Bonfire: Where art thou are quite not right even if they pass the tests in FreeCodeCamp (FCC) because they don't adhere to the instructions completely.

• Disclaimer: Please don't look into the solutions if you've not solved it yourself.

Bonfire Instruction:-

Make a function that looks through a list (first argument) and returns an array of all objects that have equivalent property values (second argument).

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Here are two solutions that exactly adhere to the instructions given in the Bonfire Challenge.

Solution 1:-

function where(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 a Boolean value for filter callback using reduce method
    return srcKeys.reduce(function (res, key) {
      // reduce to Boolean value to be returned by reduce method
      return obj.hasOwnProperty(key) && obj[key] === source[key];
    }, false);
  });
}

// should output: [ { first: 'Tybalt', last: 'Capulet' } ]
console.log(where([{ first: 'Romeo', last: 'Montague' }, { first: 'Mercutio', last: null }, { first: 'Tybalt', last: 'Capulet' }], { last: 'Capulet' }));

// should output: [ { a: 5, b: 10 } ] 
console.log(where([{ 'a': 5 }, { 'a': 5 }, { 'a': 5, 'b': 10 }], { 'a': 5, 'b': 10 }));

Solution 2:-

function where(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++) {
      // check if obj in collection doesn't have the key
      // or if it does have the key,
      // then check if the property value doesn't match the value in source
      if(!obj.hasOwnProperty(srcKeys[i]) || obj[srcKeys[i]] !== source[srcKeys[i]]) {
        return false;
      }
    }
    return true;
  });
}

// should output: [ { first: 'Tybalt', last: 'Capulet' } ]
console.log(where([{ first: 'Romeo', last: 'Montague' }, { first: 'Mercutio', last: null }, { first: 'Tybalt', last: 'Capulet' }], { last: 'Capulet' }));

// should output: [ { a: 5, b: 10 } ] 
console.log(where([{ 'a': 5 }, { 'a': 5 }, { 'a': 5, 'b': 10 }], { 'a': 5, 'b': 10 }));