Answer by Sergey Kalinichenko for If else statement with a substring

The way you check a single character to be digit is not with Integer.parseInt (that one returns, an int, not a boolean). You use Character.isDigit instead:

else if (strPos.length() > 4 && Character.isDigit(strPos.charAt(4)))

Note that it's checking the character at index 4, which is the fifth character (the initial character is at index zero, not one).