Javascript：将数组转换为对象

Question

我有数组：

[
  ['a', 'b', 'c'],
  ['a', 'h', 'k'],
  ['c', 'd', 'e']
]

有没有最好的方法在这样的对象上转换它？

{
  a: [
       ['a', 'b', 'c'],
       ['a', 'h', 'k'],
     ],
  c: [
       ['c', 'd', 'e']
     ]
}

Answer 1

您可以使用.reduce & Logical nullish assignment (??=) 来实现它

const arrays = [
  ['a', 'b', 'c'],
  ['a', 'h', 'k'],
  ['c', 'd', 'e']
];

const result = arrays.reduce((acc, curr) => {
  const key = curr[0];
  acc[key] ??= [];
  acc[key].push(curr);
  
  return acc;
}, {})

console.log(result);

Answer 2

您可以使用.reduce() 来获得所需的输出：

const data = [
  ['a', 'b', 'c'],
  ['a', 'h', 'k'],
  ['c', 'd', 'e']
];

const result = data.reduce((r, c) => {
  r[c[0]] = r[c[0]] || [];
  r[c[0]].push(c);
  return r;
}, {});

console.log(result);

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