Java examples on Java Regex

• How do I split-up string using regular expression?
• How do I create a string search and replace using regex?
• How do I do regular expression in Java?
• How do I check if a string starts with a pattern?
• How do I determine if a string match a pattern exactly?
• How do I use logical OR operator in regex?
• How do I find and replace string?
• How do I write embedded flag expression?
• How do I do boundary matching in regex?
• How do I use capturing groups in regex?
• How do I match a regex pattern in case insensitive?
• How do I count the number of capturing groups?
• How do I use quantifier in regex?
• How do I write simple character class regex?
• How do I write character class subtraction regex?
• How do I write negated character class regex?
• How do I use possessive quantifier regex?
• How do I write union character class regex?
• How do I write range character class regex?
• How do I use predefined character classes regex?
• How do I use reluctant quantifier regex?
• How do I write character class intersection regex?
• How do I combile character classes with quantifier?
• How to remove non ASCII characters from a string?
• How to truncate a string after n number of words?

How do I write range character class regex?

To define a character class that includes a range of values, put "-" metacharacter between the first and last character to be matched. For example [a-e]. You can also specify multiple ranges like this [a-zA-Z]. This will match any letter of the alphabet from a to z (lowercase) or A to Z (uppercase).

In the example below we are matching the word that begins with bat and ends with a single number that have a value range from 3 to 7.

package org.kodejava.example.util.regex;

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

public class CharacterClassesRangeClassDemo {
    public static void main(String[] args) {
        //
        // Defines regex that will search all sequences of string
        // that begin with bat and number which range [3-7]
        //
        String regex = "bat[3-7]";
        String input =
                "bat1, bat2, bat3, bat4, bat5, bat6, bat7, bat8";

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

        //
        // Creates a matcher that will match the given input
        // against this pattern.
        //
        Matcher matcher = pattern.matcher(input);

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

The program will match the following string from the input:

Text "bat3" found at 12 to 16.
Text "bat4" found at 18 to 22.
Text "bat5" found at 24 to 28.
Text "bat6" found at 30 to 34.
Text "bat7" found at 36 to 40.