How do I change the case of a string?

There are methods .toUpperCase() and .toLowerCase() which will work. For example:

You can write helper functions to do more sophisticated string case changes like changing the first letter to a capital and the rest in lower case:

function APPcapitalize(S) {
   return S.charAt(0).toUpperCase() + S.substr(1);
}

It’s usually easiest to google particular string methods.