正确是：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 scanner = new Scanner(System.in); // 读取并输出整数a int a = scanner.nextInt(); System.out.println(a); // 读取并输出整数b Long b = scanner.nextLong(); System.out.println(b); // 读取浮点数c，并保留一位小数输出 double c = scanner.nextDouble(); System.out.printf("%.1f%n", c); // 读取一个小写字母d char d = scanner.next().charAt(0); System.out.println(d); // 读取字符串e String e = scanner.next(); System.out.println(e); } }