how to do sum several arrays in javascript code example

Example 1: how to add multiple elements to A new array javascript

let vegetables = ['parsnip', 'potato']
let moreVegs = ['celery', 'beetroot']

// Merge the second array into the first one
// Equivalent to vegetables.push('celery', 'beetroot')
Array.prototype.push.apply(vegetables, moreVegs)

console.log(vegetables)  // ['parsnip', 'potato', 'celery', 'beetroot']

Example 2: sum of two array in javascript

function sumArray(a, b) {
      var c = [];
      for (var i = 0; i < Math.max(a.length, b.length); i++) {
        c.push((a[i] || 0) + (b[i] || 0));
      }
      return c;
}