Computer Science 225
Advanced Programming

Spring 2017, Siena College

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RegexPractice BlueJ Project

Click here to download a BlueJ project for RegexPractice.

RegexPractice Source Code

The Java source code for RegexPractice is below. Click on a file name to download it.

RegexPractice.java

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

/**
 * Example RegexPractice: a little testbed to have fun with regular expressions
 *
 * Jim Teresco, Siena College, Computer Science 225, Spring 2017
 *
 */

public class RegexPractice {

    public static void main(String[] args) {
	
        // this string is the regular expression we are looking for
        String regex = "\\d\\d";
        // this string is the text in which we are searching
        String text = "2-digit numbers 32 8378 hey!";
        
        // note that we don't construct a Pattern object directly, but instead
        // call the static method compile that constructs it for us
        Pattern p = Pattern.compile(regex);
        
        // the matcher method of Pattern constructs and returns a Matcher object
        // which, among other things, allows us to iterate over matching
        // substrings
        Matcher m = p.matcher(text);
        
        // Matcher's find method finds the next matching substring in the text
        // that matches the regular expression, returning true on success
        while (m.find()) {
            
            // Matcher's group method returns the substring of the most recent match
            System.out.println(m.group());
        }
    }
}