思路:
1、利用“大小写字母之间正好相差32”这一特点
2、用toLowerCase()、toUpperCase()字符串自带的方法
提示:
Java中没有.nextChar()。
所以要读取char,我们使用.next().charAt(0)
举例:Scanner scanner = new Scanner(System.in);String ret = scanner.next();char ret1 = scanner.next().charAt(0);
1、 输入小写输出大写(字符串和字符)
import java.util.Scanner;public class Test { public static void main(String[] args) {System.out.print("请输入小写字母:");Scanner scanner = new Scanner(System.in);String ret=scanner.next();System.out.println("对应的大写字母是:"+ret.toUpperCase());}}
2、输入大写输出小写(字符串和字符)
import java.util.Scanner;public class Test {public static void main(String[] args) {System.out.print("请输入大写字母:");Scanner scanner = new Scanner(System.in);String ret=scanner.next();System.out.println("对应的小写字母是:"+ret.toLowerCase());}}
3、 判断大小写并转变大小写(字符)
import java.util.Scanner;public class Test {public static void main(String[] args) {System.out.print("请输入一个字母:");Scanner scanner = new Scanner(System.in);char ret=scanner.next().charAt(0);if((ret>='a')&&(ret<='z')){ret=(char)(ret-32);System.out.println("反转大小写后的字母是:"+ret);}else if((ret>='A')&&(ret<='Z')){ret=(char)(ret+32);System.out.println("反转大小写后的字母是:"+ret);}else{System.out.println("输入错误");}}}
4、 判断大小写并转变大小写(字符串)
import java.util.Scanner;public class Test {public static void main(String[] args) {System.out.print("请输入字符串:");Scanner scanner = new Scanner(System.in);String ret = scanner.next();char[] arrays = ret.toCharArray();for (int i = 0; i < arrays.length; i++) {char c1 = arrays[i]; if (c1 >= 97 && c1 <= 122) { char c2 = (char)(c1-32);System.out.print(c2);} else if (c1 >= 65 && c1 <= 90) {char c2 = (char)(c1+32); System.out.print(c2);} else {System.out.print("/"); /*非法字符用空格代替*/}}}