License Keygen in javascript

Question

So I saw another solution on here with a problem I was having. Though the problem isn't completely solved for me.

This is the code that I found on here.

function makeid(length) {
  var result = "";
  var characters = '0123456789';
  for (var i = 0; i < length; i++) {
    result += characters[Math.floor(Math.random() * characters.length)];
  }
  result = result.match(/\d{1,4}/g).join("-");
  return result;
}

console.log(makeid(16));

And this is the current code I have now.

function makeid(length) {
  var result = "";
  var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
  for (var i = 0; i < length; i++) {
    result += characters[Math.floor(Math.random() * characters.length)];
  }
  result = result.match(/\d{1,4}/g).join("-");
  return result;
}

console.log(makeid(16));

The output is not want I want. I want the output to be in both Letters and Numbers and I'm not sure why it won't do both!

Answer 1

It's because your match() is only looking for digits ( \d ) and not any character ( . ):

function makeid(length) {
  var result = "";
  var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
  for (var i = 0; i < length; i++) {
    result += characters[Math.floor(Math.random() * characters.length)];

  }
  result = result.match(/.{1,4}/g).join("-");
  return result;
}

console.log(makeid(15));

And you can get rid of slow match all together, by using % operator:

function makeid(length) {
  var result = "";
  var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
  for (var i = 0; i < length; i++) {
    result += characters[Math.floor(Math.random() * characters.length)];
    if (i+1 < length && !((i+1) % 4))
      result += "-";
  }
  return result;
}

console.log(makeid(16));