exercise3_5.java

Introduction to java programming 一书中所有编程练习部分的源码

// Exercise3_5.java
import javax.swing.*;

public class Exercise3_5 {
    public static void main(String[] args) {
        // Prompt the user to enter input
        String yearString = JOptionPane.showInputDialog("Enter a year:");
        int year = Integer.parseInt(yearString);
        
        String monthString = JOptionPane.showInputDialog("Enter a month in the year (e.g., 1 for Jan):");
        int month = Integer.parseInt(monthString);
        
        int numberOfDaysInMonth = 0;
        
        switch (month) {
            case 1: System.out.print("January " + year);
            numberOfDaysInMonth = 31;
            break;
            case 2: System.out.print("Feburary " + year);
            if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))
                numberOfDaysInMonth = 29;
            else
                numberOfDaysInMonth = 28;
            break;
            case 3: System.out.print("March " + year);
            numberOfDaysInMonth = 31;
            break;
            case 4: System.out.print("April " + year);
            numberOfDaysInMonth = 30;
            break;
            case 5: System.out.print("May " + year);
            numberOfDaysInMonth = 31;
            break;
            case 6: System.out.print("June " + year);
            numberOfDaysInMonth = 30;
            break;
            case 7: System.out.print("July " + year);
            numberOfDaysInMonth = 31;
            break;
            case 8: System.out.print("August " + year);
            numberOfDaysInMonth = 31;
            break;
            case 9: System.out.print("September " + year);
            numberOfDaysInMonth = 30;
            break;
            case 10: System.out.print("October " + year);
            numberOfDaysInMonth = 31;
            break;
            case 11: System.out.print("November " + year);
            numberOfDaysInMonth = 30;
            break;
            case 12: System.out.print("December " + year);
            numberOfDaysInMonth = 31;
            break;
        }
        
        System.out.print(" has " + numberOfDaysInMonth + " days");
        
        
        System.exit(0);
    }
    
}