Java: Convert all the characters in a string to uppercase

Last update on May 21 2025 12:49:20 (UTC/GMT +8 hours)

30. Convert to Uppercase

Write a Java program to convert all characters in a string to uppercase.

Visual Presentation:

Sample Solution:

Java Code:

// Define a public class named Exercise30.
public class Exercise30 {
    
    // Define the main method.
    public static void main(String[] args) {
        // Declare and initialize a string variable.
        String str = "The Quick BroWn FoX!";

        // Convert the above string to all uppercase.
        String upper_str = str.toUpperCase();

        // Display the original and uppercase strings for comparison.
        System.out.println("Original String: " + str);
        System.out.println("String in uppercase: " + upper_str);
    }
}

Sample Output:

Original String: The Quick BroWn FoX!                                                                         
String in uppercase: THE QUICK BROWN FOX!  

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to convert a string to uppercase without using the built-in toUpperCase() method.
• Write a Java program to change a string to uppercase and then interleave it with a lowercase version.
• Write a Java program to convert a string to uppercase and then replace all vowels with a specified character.
• Write a Java program to transform a string to uppercase and then check if it is a palindrome.

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