JSFiddle - React, Tailwind, and code Playground
JavaScript
var array1 = [1,2,3,4,5];
var array2 = ['a', 'b', 'c', 'd', 'e','f'];
var result = array1.reduce(function(arr, v, i) {
return arr.concat(v, array2[i]);
}, []);
document.write("<pre>" +
JSON.stringify(result, null, 4) +
"</pre>");