How do I write union character class regex?

By Wayan in Regex 0 Comment

To create a single character class comprised of two or more separate character classes use unions. To create a union, simply nest one class inside the other, such as [0-3[7-9]].

package org.kodejava.regex;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class CharacterClassUnionDemo {
    public static void main(String[] args) {
        // Defines regex that matches the number 0, 1, 2, 3, 7, 8, 9
        String regex = "[0-3[7-9]]";
        String input = "0123456789";

        // Compiles the given regular expression into a pattern.
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(input);

        // Find matches and print it
        while (matcher.find()) {
            System.out.format("Text \"%s\" found at %d to %d.%n",
                    matcher.group(), matcher.start(),
                    matcher.end());
        }
    }
}

Here is the result of the program:

Text "0" found at 0 to 1.
Text "1" found at 1 to 2.
Text "2" found at 2 to 3.
Text "3" found at 3 to 4.
Text "7" found at 7 to 8.
Text "8" found at 8 to 9.
Text "9" found at 9 to 10.
Wayan
Latest posts by Wayan (see all)
Views: 2,847

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.