make a append function for string js code example
Example: how the concat function works javascript
var arr = [1, 2, 3, 4];
var arr2 = [5, 6, 7, 8];
const both = arr.concat(arr2);
console.log(both);
//[1, 2, 3, 4, 5, 6, 7, 8]var arr = [1, 2, 3, 4];
var arr2 = [5, 6, 7, 8];
const both = arr.concat(arr2);
console.log(both);
//[1, 2, 3, 4, 5, 6, 7, 8]