Question

How can I get the int value from a string such as 423e – i.e. a string that contains a number but also maybe a letter?

Integer.parseInt() fails since the string must be entirely a number.

Answer 1

Replace all non-digit with blank: the remaining string contains only digits.

Integer.parseInt(s.replaceAll("[\\D]", ""))

This will also remove non-digits inbetween digits, so "x1x1x" becomes 11.

If you need to confirm that the string consists of a sequence of digits (at least one) possibly followed a letter, then use this:

s.matches("[\\d]+[A-Za-z]?")