How do i match items of two different arrays by index in javascript ES6

Question

I have:

array1 = [ "a" , "b" , "c" , "d" ]

array2 = [ 1 ,2 ,3 ]

and the result should be:

matchedArray = [ "a1" , "b2" , "c3"]

Answer 1

Here's a simple example that should help. Try and optimize it if you can!

array1 = [ "a" , "b" , "c" , "d" ];

array2 = [ 1 ,2 ,3 ];

newArr = [];

for (let i = 0; i < array1.length; i++){
  if (array2[i])
      newArr.push(array1[i]+array2[i]) 
}

console.log(newArr);

Answer 2

It looks like you want to take the string from the same position of both arrays and combine them. If that's the case, something like this should do the trick.

const a = ['a', 'b', 'c'];
const b = [1, 2, 3, 4];

function combine(a, b) {
  const result = [];
  
  // Use both lengths and || to handle uneven arrays
  for(var i = 0; i < a.length || i < b.length; i++) {
    if (a[i] && b[i]) { // make sure they both have values
      result[i] = a[i] + b[i];
    }
  }
  
  return result;
}

console.log(combine(a, b));

Answer 3

I think what you're looking for is the map function :

let a = ["a", "b", "c", "d"];
let b = [1, 2, 3, 4, 5];
let shorterArray = a.length > b.length ? b : a;
let longerArray = b.length > a.length ? b : a;
let c = shorterArray.map((c, index) => (longerArray === a) ? longerArray[index] + c : c + longerArray[index]);
console.log(c);
//returns ["a1", "b2", "c3"]

Answer 4

You could take the minimum length of the arrays and map the values by reducing the arrays.

var array1 = ["a", "b", "c", "d"],
    array2 = [1, 2, 3],
    data = [array1, array2],
    min = Math.min(...data.map(({ length }) => length)),
    result = data.reduce((r, a) => a.slice(0, min).map((v, i) => (r[i] || '') + v), []);
    
console.log(result);

Answer 5

Easly, you'll iterate through the one and add it to the other like so.

array1 = [ "a" , "b" , "c" , "d" ];

array2 = [ 1 ,2 ,3 ];

newArray = array2.map((number, index) => {
    return array1[index] + number;
});