如何访问此嵌套对象中数组“favorite foods”的第0个索引？

Question

我尝试在下面的对象中访问数组的第0个索引：

let spaceship = {
        passengers: null,

    telescope: {
        yearBuilt: 2018,
        model: "91031-XLT",
        focalLength: 2032
    },
    crew: {
        captain: {
            name: 'Sandra',
            degree: 'Computer Engineering',
            encourageTeam() {
                console.log('We got this!')
            },
            'favorite foods': ['cookies', 'cakes', 'candy', 'spinach']
        }
    },
    engine: {
        model: "Nimbus2000"
    },
    nanoelectronics: {
        computer: {
            terabytes: 100,
            monitors: "HD"
        },
        'back-up': {
            battery: "Lithium",
            terabytes: 50
        }
    }
}; 

我尝试了以下代码：

let capFave=spaceship.crew.captain['favorite foods']['favorite foods[0]'];

和

let capFave=spaceship.crew.captain['favorite foods[0]'];

但它返回未定义或显示语法错误。

Answer 1

只需在spaceship.crew.captain['favorite foods']之后使用[0]，就像spaceship.crew.captain['favorite foods'][0]一样，因为spaceship.crew.captain['favorite foods']返回一个数组，而[0]返回一个数组的第0个索引中的值。

​

let spaceship = {
  passengers: null,

  telescope: {
    yearBuilt: 2018,
    model: "91031-XLT",
  focalLength: 2032 
  },
  crew: {
    captain: { 
      name: 'Sandra', 
      degree: 'Computer Engineering', 
      encourageTeam() { console.log('We got this!') },
      'favorite foods': ['cookies', 'cakes', 'candy', 'spinach'] 
    }
  },
  engine: {
    model: "Nimbus2000"
  },
  nanoelectronics: {
    computer: {
      terabytes: 100,
      monitors: "HD"
    },
    'back-up': {
      battery: "Lithium",
      terabytes: 50
    }
  }
};

console.log(spaceship.crew.captain['favorite foods']);
console.log(spaceship.crew.captain['favorite foods'][0]);

​