Mutations + Array.prototype.indexOf()

JavaScript
6

Sorry, I have few more questions, If you don’t mind.

Why in this Basic Code Solution: there are no “{” after if statement , it’s only after return false ? I mean I understand why… but I don’t understand How?

function mutation(arr) {
  var test = arr[1].toLowerCase();
  var target = arr[0].toLowerCase();
  for (i=0;i<test.length;i++) {
    if (target.indexOf(test[i]) === -1)
      return false;
  }
  return true;
 }

mutation(["mary", "army"]);

And I also saw your Advanced solution freeCodeCamp Algorithm Challenge Guide: Mutations
Looks like I have to learn a lot about RegExp :sweat_smile: I tried before MDN RegExp, but can’t learn a lot from it)). Can you tell me some kind of guide from where I can learn deep about RegExp?