Regex to check if the first character is uppercase

Question

I\'m trying to check that the first character of a username is capital, the following can be letters or numbers and at most 20 characters long. Can someone explain why my synta

Answer 1

I would do it like this:

var firstChar = strToCheck.substring(0, 1);

if (firstChar == firstChar.toUpperCase()) {
    // it is capital :D
}