get all the combinations between x arrays

Question

I have N arrays with objects inside. All objects has the same keys.

arr[
   {values:val1,names:someName},
   {values:val2,names:otherName},
]
arr2[
   {values:valx,names:someNamex},
   {values:valy,names:otherNamey},
]

I need to mix all the combinations between that N arrays. Something like this:

newArray[
{values:'val1''valx',names:'someName''someNamex'}
{values:'val1''valy',names:'someName''someNamey'}
{values:'val2''valx',names:'otherName''someNamex'}
{values:'val2''valy',names:'otherName''someNamey'}
]

I hope this can be helpful to find an answer to this problem.

Thanks for your time!

comb(arr: string | any[], pre?: string | undefined) { pre = pre || ' '; if (!arr.length) { return pre; } var ans = arr[0].reduce((ans: string | any[], value: string | any) => { return ans.concat(this.comb(arr.slice(1), pre + value)); } , []); return ans; } — baconitus, May 03 '22 at 20:28
Does this answer your question? [Cartesian product of multiple arrays in JavaScript](https://stackoverflow.com/questions/12303989/cartesian-product-of-multiple-arrays-in-javascript) — pilchard, May 03 '22 at 20:50

score 1 · Answer 1 · answered May 04 '22 at 03:45

Presented below is one possible way to achieve the desired objective.

Code Snippet

const myArr1 = [
   {values:'val1',names:'someName'},
   {values:'val2',names:'otherName'},
];
const myArr2 = [
   {values:'valx',names:'someNamex'},
   {values:'valy',names:'otherNamey'},
];

const arrOfArr = [...Array(5).keys()].map(x => (
  [...Array(3).keys()]
  .map(k => ({
    values: `val${x}${k}`,
    names: `someName${x}${k}`
  }))
));
//console.log(...arrOfArr);

const myConcat = (a, b, ...objs) => (
  objs.flatMap((obj) => ({
    values: `${a.values} ${b.values}`,
    names: `${a.names} ${b.names}`
  }))
);
const f = (a, b) => [].concat(...a.flatMap(d => b.flatMap(e => myConcat(d, e, []))));
const cartesian = (a, b, ...c) => (b ? cartesian(f(a, b), ...c) : a);

console.log(
  'simple test case with only 2 arrays: ', cartesian(myArr1, myArr2), '\n\n\t******\n\n'
);
console.log(
  'complex test case with 7 arrays some with 3 objects each: ',
  cartesian(myArr1, myArr2, ...arrOfArr)
);

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

Explanation

Adapts the cartesian-product answer as noted by pilchard to this context
Invokes the cartesian method for given set of arrays
Uses .myConcat() to transform the result of concatenation to have values and names string-concatenated at a per-object level

get all the combinations between x arrays

1 Answers1