How to determine if a String has non-alphanumeric characters?

Question

I need a method that can tell me if a String has non alphanumeric characters.

For example if the String is \"abcdef?\" or \"abcdefà\", the method must return true.

Answer 1

Though it won't work for numbers, you can check if the lowercase and uppercase values are same or not, For non-alphabetic characters they will be same, You should check for number before this for better usability

Answer 2

If you can use the Apache Commons library, then Commons-Lang StringUtils has a method called isAlphanumeric() that does what you're looking for.