如何从当前数组创建嵌套数组？

Question

如何根据数组中的值将此数组转换为新的嵌套数组当前阵列[{ name: 'John', review: 'Its great', book: 'Jungle Book'},{ name: 'Steve', review: 'Learned a lot', book: 'Coding Standards'},{ name: 'Chris', review: 'Love it', book: 'Coding Standards'},{ name: 'Jake', review: 'Would read again', book: 'Jungle Book'}]想做这个嵌套数组[{ book: 'Jungle Book', comment: [{   name: 'Jake',   review: 'Would read again'  },  {   name: 'John',   review: 'Its great'     }]},{ book: 'Coding Standards', comment: [{   name: 'Chris',   review: 'Love it'  },  {   name: 'Steve',   review: 'Learned a lot'     }]}]任何帮助或提示将不胜感激。

Answer 1

您的预期结果不是有效的。我认为comment这里需要一个对象数组，例如：

const temp = [{name:"John",review:"Its great",book:"Jungle Book"},{name:"Steve",review:"Learned a lot",book:"Coding Standards"},{name:"Chris",review:"Love it",book:"Coding Standards"},{name:"Jake",review:"Would read again",book:"Jungle Book"}];

const res = Object.values(temp.reduce((ac, { name, review, book }) => {

  ac[book] = ac[book] || {book, comment: []}

  ac[book].comment.push({name, review})

  return ac;

}, {}));

console.log(res);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

const arr = [{

 name: 'John',

 review: 'Its great',

 book: 'Jungle Book'

},

{

 name: 'Steve',

 review: 'Learned a lot',

 book: 'Coding Standards'

},

{

 name: 'Chris',

 review: 'Love it',

 book: 'Coding Standards'

},

{

 name: 'Jake',

 review: 'Would read again',

 book: 'Jungle Book'

}];

const result = arr.reduce(function (r, a) {

    r[a.book] = r[a.book] || [];

    r[a.book].push(a);

    return r;

}, Object.create(null));

console.log(result);

你可以做我上面做的或者_.groupBy()从 lodash 使用。