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

Use this function to check if a string is alphanumeric:

public boolean isAlphanumeric(String str)
{
    char[] charArray = str.toCharArray();
    for(char c:charArray)
    {
        if (!Character.isLetterOrDigit(c))
            return false;
    }
    return true;
}

It saves having to import external libraries and the code can easily be modified should you later wish to perform different validation checks on strings.