javascript

Question

所以，假设我有这个：

var officers = [
  { id: 20, name: 'Captain', lastName: 'Piett' },
  { id: 24, name: 'General', lastName: 'Veers'  },
  { id: 56, name: 'Admiral', lastName: 'Ozzel'  },
  { id: 88, name: 'Commander', lastName: 'Jerjerrod'  }
];

如果我这样做： var officersIds = officers.map(x => [x.name, x.lastName]); officersIds 的结果将是这样的：

[ "Captain", "Piett" ], [ "General", "Veers" ], [ "Admiral", "Ozzel" ], [ "Commander", "Jerjerrod" ]

对吗？

所以，我需要做的是在每次地图迭代中放置一个对象，这样输出现在就是这样的，例如：

[["x", "y"], [ "Captain", "Piett" ]], 
[["x", "y"], [ "General", "Veers" ]],  
[["x", "y"], [ "Admiral", "Ozzel" ]], 
[["x", "y"], [ "Commander", "Jerjerrod" ]]

为什么我需要这个？最好不要问 ;) 但这是一个复杂的问题，如果你能帮助我解决这个简单的问题，我可以将你的解决方案转移到我的复杂问题上。

重要提示：有没有办法在一行中完成此操作？

Answer 1

var officers = [
  { id: 20, name: 'Captain', lastName: 'Piett' },
  { id: 24, name: 'General', lastName: 'Veers'  },
  { id: 56, name: 'Admiral', lastName: 'Ozzel'  },
  { id: 88, name: 'Commander', lastName: 'Jerjerrod' },
];

officers.unshift({ name: x, lastName: y });

var officersIds = officers.map(x => [x.name, x.lastName]);

或者

var officers = [
      { id: 20, name: 'Captain', lastName: 'Piett' },
      { id: 24, name: 'General', lastName: 'Veers'  },
      { id: 56, name: 'Admiral', lastName: 'Ozzel'  },
      { id: 88, name: 'Commander', lastName: 'Jerjerrod' },
    ];


    var officersIds = officers.map(x => [x.name, x.lastName]);

    officersIds.unshift(["x", "y" ]);

Answer 2

在 officers 上使用地图。

var officers = [
  { id: 20, name: 'Captain', lastName: 'Piett' },
  { id: 24, name: 'General', lastName: 'Veers'  },
  { id: 56, name: 'Admiral', lastName: 'Ozzel'  },
  { id: 88, name: 'Commander', lastName: 'Jerjerrod'  }
];

var officersIds = officers.map(x => [["x", "y"], [x.name, x.lastName]]);
   
console.log(officersIds);

Answer 3

如果您只想将 ['x', 'y'] 添加到数组的开头，您可以使用 spread operator 使其成为一行：

var officersIds = [['x', 'y'], ...officers.map(x => [x.name, x.lastName])];

请参阅下面的概念验证：

var officers = [
  { id: 20, name: 'Captain', lastName: 'Piett' },
  { id: 24, name: 'General', lastName: 'Veers'  },
  { id: 56, name: 'Admiral', lastName: 'Ozzel'  },
  { id: 88, name: 'Commander', lastName: 'Jerjerrod'  }
];

var officersIds = [['x', 'y'], ...officers.map(x => [x.name, x.lastName])];

console.log(officersIds);

但是，如果您想将 ['x', 'y'] 添加到数组中的每个项目，那么您应该改为这样做：

var officersIds = officers.map(x => [['x', 'y'], [x.name, x.lastName]]);

var officers = [
  { id: 20, name: 'Captain', lastName: 'Piett' },
  { id: 24, name: 'General', lastName: 'Veers'  },
  { id: 56, name: 'Admiral', lastName: 'Ozzel'  },
  { id: 88, name: 'Commander', lastName: 'Jerjerrod'  }
];

var officersIds = officers.map(x => [['x', 'y'], [x.name, x.lastName]]);

console.log(officersIds);

Answer 4

您可以将需要的部分添加到映射函数中。

var officers = [{ id: 20, name: 'Captain', lastName: 'Piett' }, { id: 24, name: 'General', lastName: 'Veers'  }, { id: 56, name: 'Admiral', lastName: 'Ozzel'  }, { id: 88, name: 'Commander', lastName: 'Jerjerrod'  }],
    officersIds = officers.map(x => [["x", "y"], [x.name, x.lastName]]);

console.log(officersIds);

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