Java语言程序设计（基础篇）第十版 4.18

public class J4_18 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		java.util.Scanner input = new java.util.Scanner(System.in);
		System.out.print("Enter two characters: ");
		String ch = input.nextLine();

		char ch1 = ch.charAt(0);
		char ch2 = ch.charAt(1);
		if(ch1 == 'M')
			System.out.print("Mathematics ");
		else if(ch1 == 'C')
			System.out.print("Computer Science ");
		else if(ch1 == 'I')
			System.out.print("informantion  technology ");
		else
		{
			System.out.println("Invalid input");
			System.exit(0);
		}

		if(ch2 == '1')
			System.out.println(" Freshman");
		else if(ch2 == '2')
			System.out.println(" Sophomore");
		else if(ch2 == '3')
			System.out.println("Junior");
		else
			System.out.println("Senior");
	}

}