JSFiddle - React, Tailwind, and code Playground

by M. Junaid Salaat

JavaScript

var sum = function(x) {
  if (!x) x = 0;
  var foo = function(y) {
   if (!y) return x;
    else return sum(x + y);
  };
  foo.toString = function() {
    return x;
  };
   return foo;
}
var s = sum();
alert(s); // 0
alert(s(1)); // 1
alert(s(1)(2)); //3
alert(s(3)(4)(5)); // 12