1 package Pro1;
2
3 public class Test { 4 public static void main(String[] args) { 5 String str = "Hello World"; 6 char[] c = str.toCharArray(); 7 StringBuffer buffer = new StringBuffer(); 8 9 for (int i = str.length() - 1; i >= 0; i--) { 10 if ((c[i] >= 'A') && (c[i] <= 'Z')) { 11 buffer.append(String.valueOf(c[i]).toLowerCase()); 12 } else if ((c[i] >= 'a') && (c[i] <= 'z')) { 13 buffer.append(String.valueOf(c[i]).toUpperCase()); 14 } 15 } 16 System.out.println(buffer.toString()); 17 } 18 }
1 package pro2;
2 import java.util.Random; 3 public class Test2 { 4 public static void main(String[] args) { 5 Random rand = new Random(); 6 int[] num = new int[5]; 7 for (int i = 0; i < num.length; i++) { 8 num[i] = 20 + rand.nextInt(31); 9 System.out.println(num[i]); 10 } 11 } 12 }