Here, is the output of uppercase program.

ConvetUppercase.java

import java.io.*;
import java.util.Scanner;

public class ConvetUppercase{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Welcome to Letter converter!");
System.out.println("Enter the letter of alphabet in lowercase!");
String str = scan.next();
str.substring(0, 97);
String str1 = str.substring(0, 97);
str1.toUpperCase();
System.out.println("The alphabet letter in Uppercase="+str1);
}
}

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run the given above program code and get to the output in uppercase letter.

amar