JSFiddle - React, Tailwind, and code Playground
JavaScript
var main = [];
var t1 = [1,2,3,4,5,6,7,8,9];
var t2 = [10,11,12,13,14,15];
main = main.concat(t1);
console.log(main);
main = main.concat(t2);
console.log(main);
var main = [];
var t1 = [1,2,3,4,5,6,7,8,9];
var t2 = [10,11,12,13,14,15];
main = main.concat(t1);
console.log(main);
main = main.concat(t2);
console.log(main);