This example show you how to attach quantifier to character classes or capturing group in regular expressions.

package org.kodejava.example.regex; import java.util.regex.Pattern; import java.util.regex.Matcher; public class CombineWithQuantifier { public static void main(String[] args) { // [abc]{3} --> apply quantifier in character class. // Find 'a' or 'b' or 'c', three times in a row. // // (abc){3} --> apply quantifier in capturing group. // Find 'abc', three times in a row. // // abc{3} --> apply quantifier in character class. // Find character 'c', three times in a row. String[] regexs = {"[abc]{3}", "(abc){3}", "abc{3}"}; String text = "abcabcabcabcaba"; for (String regex : regexs) { Pattern pattern = Pattern.compile(regex); Matcher matcher = pattern.matcher(text); // Find every match and print it System.out.format("Regex: %s %n", regex); while (matcher.find()) { System.out.format("Text \"%s\" found at %d to %d.%n", matcher.group(), matcher.start(), matcher.end()); } System.out.println("------------------------------"); } } } 

This program will print the following output:

Regex: [abc]{3} Text "abc" found at 0 to 3. Text "abc" found at 3 to 6. Text "abc" found at 6 to 9. Text "abc" found at 9 to 12. Text "aba" found at 12 to 15. ------------------------------ Regex: (abc){3} Text "abcabcabc" found at 0 to 9. ------------------------------ Regex: abc{3} ------------------------------