javascript - オブジェクトの配列内から JavaScript 関数にアクセスしようとしています

Question

基本的に、これらのギターの評価を出力したいのですが、「TypeError: taylorGuitar.guitarRating は関数ではありません。コードは次のとおりです。

    var taylorGuitar = [


{
    "model": "814ce",
    "stringsCount": 6,
    "pickup": true,
    "stringsTuning": ["E", "A", "D", "G", "B", "E"],
    "playabilityRating": 8,
    "soundRating": 10,
    "lookRating": 10,
    "woods": {
        "front": "Cedar",
        "back": "Rosewood",
        "fretboard": "Rosewood"
             }
},
{
    "model": "410ce",
    "stringsCount": 6,
    "pickup": true,
    "stringsTuning": ["E", "A", "D", "G", "B", "E"],
    "playabilityRating": 8,
    "soundRating": 9,
    "lookRating": 8,
    "woods": {
        "front": "Cedar",
        "back": "Rosewood",
        "fretboard": "Rosewood"
             }
},
{
        "guitarRating":  function(){
        totalScore = taylorGuitar.playabilityRating + taylorGuitar.soundRating + taylorGuitar.lookRating;
        return totalScore;
        }
}



];

var rating = taylorGuitar.guitarRating();
console.log(rating);