大小写字母转换（java实现）两种方法。

题目

从键盘输入一个小写字母，然后输入出对应的大写字母，用两种输入输入的方法实现。第一种使用控制输入输出，第二种是使用对话框输入输出。
第一种方法
代码实现

import java.util.Scanner;    
public class zdz {
    public static void main (String args[]) {
        System.out.printf("Please write a minuscule：");
        Scanner letter = new Scanner (System.in);
        char zm = letter.next().charAt(0);  
        while(zm < 'a' || zm > 'z') {
            System.out.println("It is not  right Please write again");
            System.out.printf("Please write a minuscule：");
            zm = letter.next().charAt(0);
        }
        System.out.printf( zm + "All  caps ");
        zm = (char)(zm - 32);     
        System.out.println(zm);
    }
}

运行结果

第二种方法
代码实现

import javax.swing.JOptionPane;    
public class zdz {
    public static void main (String args[]) {
        String zm = JOptionPane.showInputDialog(null , "Please write a minuscule：" , "write" , JOptionPane.QUESTION_MESSAGE);   
        char letter1 = zm.charAt(0);    
         while(letter1 < 'a' || letter1 > 'z') {
            zm = JOptionPane.showInputDialog(null , "No!Please write a minuscule again" , "write" , JOptionPane.QUESTION_MESSAGE);
            letter1 = zm.charAt(0);
        }
        char letter2 = (char)(letter1 - 32);
        JOptionPane.showMessageDialog(null , letter1 + "capitalization：" + letter2, "export" , JOptionPane.INFORMATION_MESSAGE);    
    }
}

运行结果