Match a string against multiple regex patterns

Question

I have an input string.

I am thinking how to match this string against more than one regular expression effectively.

Example Input: ABCD

Answer 1

I'm not sure what effectively means, but if it's about performance and you want to check a lot of strings, I'd go for this

...
static Pattern p1 = Pattern.compile("[a-zA-Z]{3}");
static Pattern p2 = Pattern.compile("^[^\\d].*");
static Pattern p3 = Pattern.compile("([\\w&&[^b]])*");

public static boolean test(String s){
   return p1.matcher(s).matches ? true: 
        p2.matcher(s).matches ? true: 
        p3.matcher(s).matches;
}

I'm not sure how it will affect performance, but combining them all in one regexp with | could also help.