public static void main(String[] args) { Scanner in = new Scanner(System.in); while (in.hasNext()) { String input = in.nextLine(); //输入 if (input == null){ //判断是否为空 break; } char upChar = input.charAt(0); //转成 单个字符 if (upChar >= 'A' && upChar <= 'Z'){ //判断是否正确 char lowerCh = (char)(upChar + 32); //转小写 System.out.println(lowerCh); } else { break; } } in.close(); }
import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner read = new Scanner(System.in); while(read.hasNext()){ String a = read.nextLine(); a=a.toLowerCase(); System.out.println(a); } } }
import java.util.*; public class Main { public static void main(String [] args) { Scanner input=new Scanner(System.in); String score; while(input.hasNextLine()) { score=input.nextLine(); for(int i=0;i<score.length();i++){ if('A'<=score.charAt(i)&&score.charAt(i)<='Z')//大写转小写 { String score1=score.toLowerCase(); System.out.println(score1.charAt(i)); } else if('a'<=score.charAt(i)&&score.charAt(i)<='z')//小写转大写 { String score2=score.toUpperCase(); System.out.println(score2.charAt(i)); } else{//法非输入 // return 0; System.out.println("非法输入"); } } } } }