import java.util.Scanner; public class Main{ public static void main(String[] args){ Scanner sc = new Scanner(System.in); String str = sc.nextLine(); //[^a-zA-Z]是去匹配目标字符串中非a—z也非A—Z的字符,将所有非字母字符替换为空 String str1 = str.replaceAll("[^a-zA-Z]",""); //将所有非空格的替换为空 String str2 = str.replaceAll("[^ ]",""); //...
