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HTML

              
                
              
            
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CSS

              
                
              
            
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JS

              
                


// Setup
// recordCollection is a object which contains nested object id inside it. id contains individiual properties
var recordCollection = {
  2548: {
    albumTitle: 'Slippery When Wet',
    artist: 'Bon Jovi',
    tracks: ['Let It Rock', 'You Give Love a Bad Name']
  },
  2468: {
    albumTitle: '1999',
    artist: 'Prince',
    tracks: ['1999', 'Little Red Corvette']
  },
  1245: {
    artist: 'Robert Palmer',
    tracks: []
  },
  5439: {
    albumTitle: 'ABBA Gold'
  }
};

// update records is a function which will  reform the object recordCollection acording to given conditions and return it
function updateRecords(records, id, prop, value) {
  if (prop!= 'tracks' && value!='') {
    records[id][prop]=value;
  }else if (prop==='tracks' &&records[id].hasOwnProperty('tracks')===false) {
    records[id][prop]=[value];
  }else if(prop==='tracks' &&value!="") {
    records[id][prop].push(value);
  }else if(value==="") {
    delete records[id][prop];
  }
   return records[id][prop] }

 console.log(updateRecords(recordCollection, 5439, "tracks", "Take a Chance on Me"));
// my problem or confusion is that tracks is already a array which contains string value inside in the object recordCollection
// so why do i have to use it or compare it like this "tracks"? 
//and when i use it as tracks not "tracks" why there is an eror tracks undefined

// if (prop!= 'tracks' && value!='') {
 //   records[id][prop]=value;
  // }
// else if (prop==='tracks' &&records[id].hasOwnProperty('tracks')===false) {
   // records[id][prop]=[value];
  // }
// else if(prop==='tracks' &&value!="") 
              
            
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