# Java: Capitalize - Solution

See Exercise - Capitalize programming exercise.

Method to change the first character to uppercase.

    public static String capitalize(String s) {
        if (s.length() == 0) {
            return s;
        } else {
            return s.substring(0,1).toUpperCase() + s.substring(1);
        }
    }

For the extra credit part, just an a null test to the if statement.

        if (s == null || s.length() == 0) {

Because of short circuit evaluation, if s is null, the "or" operation is true and it doesn't even have to evaluate the second part, and therefore the null won't cause a NullPointerException.