将 object 与 arrays 转换为对象数组的最佳方法，反之亦然

Question

what is the best way to convert an object of arrays to an array of objects and vice-versa

{
  category : ['a','b','c'],
  title : ['e','f','g'],
  code : ['z','x','v']
}

To

[
  {
    category : 'a',
    title : 'e',
    code : 'z'
  },
  {
    category : 'b',
    title : 'f',
    code : 'x'
  },
  {
    category : 'c',
    title : 'g',
    code : 'v'
  },
]

Answer 1

You could use two function for generating an array or an object. They works with

• Object.keys for getting all own property names,

• Array#reduce for iterating an array and collecting items for return,

• Array#forEach just fo itarating an array.

 function getArray(object) { return Object.keys(object).reduce(function (r, k) { object[k].forEach(function (a, i) { r[i] = r[i] || {}; r[i][k] = a; }); return r; }, []); } function getObject(array) { return array.reduce(function (r, o, i) { Object.keys(o).forEach(function (k) { r[k] = r[k] || []; r[k][i] = o[k]; }); return r; }, {}); } var data = { category: ['a', 'b', 'c'], title: ['e', 'f', 'g'], code: ['z', 'x', 'v'] }; console.log(getArray(data)); console.log(getObject(getArray(data))); 

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Answer 2

Here is solution using reduce method and arrow function.

 var obj={ category : ['a','b','c'], title : ['e','f','g'], code : ['z','x','v'] } var result=obj[Object.keys(obj)[0]].reduce((a,b,i)=>{ var newObj={}; Object.keys(obj).forEach(function(item){ newObj[item]=obj[item][i]; }); return a.concat(newObj); },[]); console.log(result); 

Answer 3

You can use map() and forEach()

 var obj = { category : ['a','b','c'], title : ['e','f','g'], code : ['z','x','v'] } var result = Object.keys(obj).map(function(e, i) { var o = {} Object.keys(obj).forEach((a, j) => o[a] = obj[a][i]) return o }) console.log(result) 

Answer 4

Not an answer to the original question, but thought I'd share this as I came here looking for a solution to a related problem: I needed the Cartesian product of values of uneven length. What I'm using for that:

 /** * Get the Cartesian product of a list of array args. */ const product = (...args) => args.length === 1? args[0].map(x => [x]): args.reduce( (a, b) => Array.from(a).flatMap( v1 => Array.from(b).map(v2 => [v1, v2].flat()) ) ); /** * Map[String,Array[Any]] -> Array[Map[String,Any]] */ const arrayValuesToObjectArray = (obj) => product(...Object.values(obj)).map(values => Object.fromEntries( Object.keys(obj).map((k, idx) => [k, values[idx]]) )); console.log(arrayValuesToObjectArray({ hello: ["this", "is", "a", "test"] })); console.log(arrayValuesToObjectArray({ one: ["foo"], two: ["bar", "baz"], three: ["this", "is", "three"], })); console.log(arrayValuesToObjectArray({ one: "foo", two: "bar baz", three: "this is three", }));