Character class p{javaUpperCase} Java regex.

This character class \p{javaUpperCase} matches upper case letters. This class matches the characters which returns true when passed as a parameter to the isUpperCase() method of the java.lang.Character class.

Example 1

 Live Demo

import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a string");       Scanner sc = new Scanner(System.in);       String input = sc.nextLine();       //Regular expression       String regex = "[\p{javaUpperCase}]";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       int count = 0;       while(matcher.find()) {          count++;       }       System.out.println("Number of upper case characters: "+count);    } }

Output

Enter a string This IS A sample TExt Number of lower case characters: 6

Example 2

 Live Demo

import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example {    public static void main( String args[] ) {       //Regular expression to match lower case letters       String regex = "^\p{javaUpperCase}+$";       //Getting the input data       Scanner sc = new Scanner(System.in);       System.out.println("Enter 5 input strings: ");       String input[] = new String[5];       for (int i=0; i<5; i++) {          input[i] = sc.nextLine();       }       //Creating a Pattern object       Pattern p = Pattern.compile(regex);       System.out.println("Strings with only upper case characters: ");       for(int i=0; i<5;i++) {          //Creating a Matcher object          Matcher m = p.matcher(input[i]);          if(m.matches()) {             System.out.println(m.group());          }       }    } }

Output

Enter 5 input strings: Raju RAMU rahman radha SUnDar* Strings with only upper case characters: RAMU