Java Case-Insensitive Regular Expression Example

Java case-insensitive regular expression

By setting the Pattern.CASE_INSENSITIVE flag, we can have case-insensitive matching.

The example performs a case-insensitive matching of the regular expression.

package net.javaguides.corejava.regex;

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

public class JavaRegexCaseInsensitive {

    public static void main(String[] args) {

        List < String > users = Arrays.asList("dog", "Dog", "DOG", "Doggy");

        Pattern p = Pattern.compile("dog", Pattern.CASE_INSENSITIVE);

        users.forEach((user) - > {

            Matcher m = p.matcher(user);

            if (m.matches()) {
                System.out.printf("%s matches%n", user);
            } else {
                System.out.printf("%s does not match%n", user);
            }
        });
    }
}

Output:

dog matches
Dog matches
DOG matches
Doggy does not match

Reference

https://www.javaguides.net/2019/12/java-regex-tutorial-regular-expressions.html