Java Program to Convert a String to Uppercase

Introduction

Converting a string to uppercase is a basic operation in text processing. This task helps you understand how to manipulate strings using built-in methods in Java. This guide will walk you through writing a Java program that converts a given string to uppercase.

Problem Statement

Create a Java program that:

• Prompts the user to enter a string.
• Converts the entire string to uppercase.
• Displays the uppercase string.

Example:

• Input: "hello world"
• Output: "HELLO WORLD"

Solution Steps

1. Read the String: Use the Scanner class to take the string as input from the user.
2. Convert the String to Uppercase: Use the toUpperCase() method to convert the string to uppercase.
3. Display the Uppercase String: Print the converted string.

Java Program

// Java Program to Convert a String to Uppercase
// Author: https://www.rameshfadatare.com/

import java.util.Scanner;

public class StringToUppercase {
    public static void main(String[] args) {
        // Step 1: Read the string from the user
        try (Scanner scanner = new Scanner(System.in)) {
            System.out.print("Enter a string: ");
            String input = scanner.nextLine();
            
            // Step 2: Convert the string to uppercase
            String uppercaseString = input.toUpperCase();
            
            // Step 3: Display the uppercase string
            System.out.println("Uppercase string: " + uppercaseString);
        }
    }
}

Explanation

Step 1: Read the String

• The Scanner class is used to read a string input from the user. The nextLine() method captures the entire line as a string.

Step 2: Convert the String to Uppercase

• The toUpperCase() method of the String class is used to convert the entire string to uppercase.

Step 3: Display the Uppercase String

• The program prints the converted uppercase string using System.out.println().

Output Example

Example:

Enter a string: hello world
Uppercase string: HELLO WORLD

Conclusion

This Java program demonstrates how to convert a user-input string to uppercase. It covers essential concepts such as string manipulation and using built-in methods, making it a valuable exercise for beginners learning Java programming.