How do I pair arrays with the first one being a normal array and second one an array of arrays in JavaScript?

Question

Given the following arrays:

var arr1 = ['A','B','C'];
var arr2 = [['D','E','F']['G','H','I']]

The output should be:

['ADG','ADH','ADI','AEG','AEH','AEI','AFG','AFH','AFI','BDG','BDH','BDI'.....]

But it should also be dynamic so that if another array is added to arr2 it should pick that as well.

This is what I currently have:

const arrays = (arr1 = [], arr2 = [],arr3 = []) => {

  // var arr3 = arr2.slice(3);
  const res = [];
  for(let i = 0; i < arr1.length; i++){
    for(let j = 0; j < arr2.length; j++){
      for(let s=0;s<arr3.length;s++){
        res.push(arr1[i] + arr2[j] + arr3[s] );
      }
    }
  }

  return res;
};

Answer 1

The fact that you have those two different array variables is immaterial. Could just throw everything together ¹ and use reduceRight() :

 const arrays = [['A','B','C'], ['D','E','F'], ['G','H','I']]; const combine = (arrays) => arrays.reduceRight((a, v) => v.flatMap(c => a.map(r => c + r))); console.log(combine(arrays));

---

^{1 For your case that would be as simple as const arrays = [arr1, ...arr2];}

Answer 2

 var arr1 = ['A','B','C']; var arr2 = [['D','E','F'],['G','H','I'],['J','K','L'],['M','N','O']]; const arr3 = []; arr1.forEach((item,index)=>{ if(arr2.length >= index) { arr2.forEach((el,i)=>{ el.forEach((char,charIndex)=>{ let combination = item combination += char for(let j=1;j<arr2.length;j++){ if(arr2[j]){ combination += arr2[j][charIndex] } } arr3.push(combination) }) }) } }) console.log(arr3)

here is what I did