Untitled

<!DOCTYPE html>
<html>

  <head>
    <link rel="stylesheet" href="style.css">
  </head>

  <body>

  </body>
  <script src="script.js"></script>
</html>

function bind(f, th) {
  var finalArgs = [].slice.call(arguments, 2);
  return function() {
    if (arguments) {
      finalArgs = finalArgs.concat([].slice.call(arguments));
    }
    return f.apply(th, finalArgs);
  };
}

function sum(a, b, c) {
  log("sum inner", a, b, c);
  return a + b + c;
}

function sumThis(a, b, c) {
  log("sumThis inner", this.val, a, b, c);
  return this.val + a + b + c;
}

log(bind(sum, null, 1)(2, 3));

log(bind(sum, null)(1, 2, 3));

log(bind(sumThis, {val: 4}, 1)(2, 3));

function log() {
  document.body.innerHTML += "<br>" + [].slice.call(arguments).join(", ");
}

/* Styles go here */