How to use Metacharacter subtraction class | Java Regex | Java Regular Expressions | Regex in java

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RegexDemo.java

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

/**
 *
 * Subtraction Class
 *
 */
public class RegexDemo
{

    public static void main(String[] args)
    {
        /*
         * We will get 8 matches because the Subtraction of the two
         * sets has only 8 elements.
         */
        calculateMatches("[0-9&&[^12]]", "0123456789");
        calculateMatches("[0-9&&[^12]]", "123");
    }

    private static void calculateMatches(String regex, String inputText)
    {
        Pattern pattern = Pattern.compile(regex);
        Matcher matcher = pattern.matcher(inputText);
        int matches = 0;

        /*
         * The find method keeps advancing through the input text and
         * returns true for every match, so we can use it to find the
         * match count as well:
         */
        while (matcher.find())
        {
            ++matches;
        }
        System.out.println("Number of Matches = " + matches);
    }

}

Output

Number of Matches = 8
Number of Matches = 1

Click the below link to download the code:
https://sites.google.com/site/ramj2eev1/home/javabasics/RegexDemo_substraction_class.zip?attredirects=0&d=1

Github Link:
https://github.com/ramram43210/Java/tree/master/BasicJava/RegexDemo_substraction_class

Bitbucket Link:
https://bitbucket.org/ramram43210/java/src/9ca0aed85cf523c7d53f60f93dd6c7d098a3db63/BasicJava/RegexDemo_substraction_class/?at=master

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