Java- Find all Capital Letters in the String

By Atul Rai | Last Updated: May 30, 2021 Previous       Next

In this short tutorial, we’ll find all the capital letters in the given String using Java. Character.isUpperCase(char ch) returns true if the given character is a capital letter.

For example, we have an employee name i.e “juHi GuPta”, in this string H, G, and P is the capital letter.

package org.websparrow;

import java.util.function.Predicate;

public class FindCapitalLetter {

	public static void main(String[] args) {

		findCapitalUsingPredicate("ManisH fartIyaL");

		findCapital("juHi GuPta");

	}

	// using java functional interface Predicate
	private static void findCapitalUsingPredicate(final String name) {
		System.out.print("Capita Letters in " + name + ": ");
		
		Predicate<Character> predicate = Character::isUpperCase;

		for (int i = 0; i < name.length(); i++) {

			if (predicate.test(name.charAt(i))) {
				System.out.print(name.charAt(i));
			}
		}
		System.out.println();
	}

	private static void findCapital(final String name) {
		System.out.print("Capita Letters in " + name + ": ");
		
		for (int i = 0; i < name.length(); i++) {

			if (Character.isUpperCase(name.charAt(i))) {
				System.out.print(name.charAt(i));
			}
		}
	}

}

Output:

Capita Letters in ManisH fartIyaL: MHIL
Capita Letters in juHi GuPta: HGP

References

1. How to sort Map by Key or Value in Java 8
2. How to sort list in Java 8