My Switch statement is not working as expected

Question

I am currently trying to finish this program, however when I am testing my switch statement, it goes directly to my default case and says that I have entered invalid information.

My Task

I have to receive a month from the user and send it to my case statement in order to execute my code for the certain case. As you may notice, that each case has a key in it, this key is for personal purposes. Please disregard.

My Problem

case statement goes directly into my default statement, which issues an invalid information message to the user.

My Progress

This will be my complete program, everything seems to work properly except that my case statement recognizes every month as invalid input

// Import Libraries
    import javax.swing.*;
    import java.util.*;
    import java.io.*;


// This is my program.
public class DateCalc

{
public static void main (String[] args)
{
    String month;
    String day;
    String inputYear;
            Scanner  keyboard = new Scanner(System.in); 

                // receiving input for my age variable
                System.out.print( "Please Enter The Month Of The Date :");
                month = keyboard.nextLine();
                // receiving input for my weight variable
                System.out.print( "Please Enter The Day Of The Date : ");
                day = keyboard.nextLine();
                // receiving input for my height variable
                System.out.print( "Please Enter The Year OF The Date : ");
                inputYear = keyboard.nextLine();
                String stringYear = ""+ inputYear.charAt(inputYear.length()-2) + inputYear.charAt(inputYear.length()-1);
                int year = Integer.parseInt(stringYear);
                int intDay = Integer.parseInt(day);

        switch(month) 
        {  

          // I tried to test my program by using my first case " January ", However it goes right through every case directly for my default case.  

            case "January || january" :
            int janKey = 1;
            int janQuarter = year / 4;
            int janSum = year + janQuarter + intDay + janKey;

            System.out.print( " Date Entered Was : " + month + ","+ day + "" + inputYear);
            System.out.print( " Last Two Digits Of The Year Were : " + year);
            System.out.print( " One Quarter Of Last Two Digits : " + janQuarter);
            System.out.print( " The Given Day Of The Month Entered : " + day);
            System.out.print( " The Index Key This Moth is : " + janKey);
            System.out.print( " The Sum Of All The number Above is : " + janSum);
            System.out.print( " \n \n The Day Of The Week Was : ");
            int weekDay = dayLookUp(janSum);
            System.out.print( " \n \n The Day Of The Week Was : " + weekDay);
            break;


            case "February || february":  
            int febKey = 4;
            break;  


            case "March || march":  
            int marKey = 4;
            break;


            case "April || april":  
            int aprKey = 0; 
            break;

            case "May || may":  
            int maykey = 2; 
            break;

            case "June || june":  
            int junKey = 5; 
            break;

            case "July || july":  
            int julKey = 0; 
            break;

            case "August || august":  
            int augKey = 3; 
            break;

            case "September || september":  
            int septKey = 6; 
            break;

            case "October || october":  
            int octKey = 1; 
            break;

            case "November || november":  
            int novKey = 4; 
            break;

            case "December || december":  
            int decKey = 4; 
            break;

            //  IN MY DEFUALT CASE " inputValidation " WILL BE EXECUTED
            default:
            JOptionPane.showMessageDialog(null," Invalid Entry Please Try Again " );

        }
}

public static int dayLookUp ( int janSum )
{
    int sum = janSum;
    int day = 14 % 7;
    return day;

}
}

Answer 1

You cannot test for alternatives this way, case "January || january": doesn't work. You can give alternatives with multiple cases

switch (month) {
case "january":
case "January":
    int janKey = 1;

without an intervening break. This causes a fall through to the second case, when january is entered. The same is with the other months, of course.

Answer 2

The mistake is at "January || january" this is one String use case "January": case "january":

Answer 3

The way you're doing it now, it's looking for the whole string as is, literally, not interpreting the || as any form of or.

You can either set the element in the switch to uppercase or lowercase use :

switch(month.toLowerCase()) {
    case "january" :
        ...
        break;
    case "february":
        ...
    ...
}

or you have to double case elements:

switch (month) {
    case "January":
    case "january":
       ...
       break;
    case "February":
    case "february":
        ...
    ...
}