JSFiddle - React, Tailwind, and code Playground
JavaScript
var line = "4";
var m = Math.pow(10,parseInt(line))-1;
var c=0;
for (var i=11;i<=m;i++) {
var t = i+"";
var l = t.length;
var a = l/2;
var t1 = t.substr(0,a).split("");
var t2 = t.substr(a, l).split("");
if (arrSum(t1) === arrSum(t2)) {
c+=1;
//console.log(t1, t2)
}
}
console.log(c);
function arrSum(arr) {
var count=0;
for (var i=arr.length; i--;) {
count+=parseInt(arr[i]);
}
return count;
}