RegexExample4.java

// Regular Expression Character classes and Quantifiers Example
import java.util.regex.*;  
class RegexExample4{  
public static void main(String args[]){  
System.out.println("? quantifier ....");  
System.out.println(Pattern.matches("[amn]?", "a"));//true (a or m or n comes one time)  
System.out.println(Pattern.matches("[amn]?", "aaa"));//false (a comes more than one time)  
System.out.println(Pattern.matches("[amn]?", "aammmnn"));//false (a m and n comes more than one time)  
System.out.println(Pattern.matches("[amn]?", "aazzta"));//false (a comes more than one time)  
System.out.println(Pattern.matches("[amn]?", "am"));//false (a or m or n must come one time)  
  
System.out.println("+ quantifier ....");  
System.out.println(Pattern.matches("[amn]+", "a"));//true (a or m or n once or more times)  
System.out.println(Pattern.matches("[amn]+", "aaa"));//true (a comes more than one time)  
System.out.println(Pattern.matches("[amn]+", "aammmnn"));//true (a or m or n comes more than once)  
System.out.println(Pattern.matches("[amn]+", "aazzta"));//false (z and t are not matching pattern)  
  
System.out.println("* quantifier ....");  
System.out.println(Pattern.matches("[amn]*", "ammmna"));//true (a or m or n may come zero or more times)  
  
}}