is it possible to check if a char matches a list of possibilities?

Question

For example I know that when checking strings, you can do something like

if (string.matches(\"a|e|i|o|u|A|E|I|O|U\" ) )
{
   // Then do this code.
}
<         


        

Answer 1

You could make a collection of chars that you want to check, and see if the collection contains the char in question. A HashSet is ideal here for O(1) look up time. (not that it matters, because the size is constant.)

private static final HashSet vowels = new HashSet();

//Initialize vowels hashSet to contain vowel characters
static{
    vowels.add('a');
    vowels.add('e');
    vowels.add('i');
    vowels.add('o');
    vowels.add('u');
    vowels.add('A');
    vowels.add('E');
    vowels.add('I');
    vowels.add('O');
    vowels.add('U');
}

public static boolean isVowel(Character c){
    return vowels.contains(c);
}