DayToNumberOfWeek.java

import java.util.Scanner;
public class DayToNumberOfWeek {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.println("Enter the Day");
        String day = in.nextLine();
        switch (day.toLowerCase()) {
            case "sunday":
                System.out.println("1");
                break;
            case "monday":
                System.out.println(2);
                break;
            case "tuesday":
                System.out.println(3);
                break;
            case "wednesday":
                System.out.println(4);
                break;
            case "thursday":
                System.out.println(5);
                break;
            case "friday":
                System.out.println(6);
                break;
            case "saturday":
                System.out.println(7);
                break;
            default:
                System.out.println("Invalid ");
        }
        in.close();
    }
}