CODEWITHSUNDEEP
java
Truck Whale
Truck Whale

Reputation: 37

getting wrong day with dayofweek

i'm trying to make a simple program with java the user will input his birthday and the app give him the date this is my code

import java.util.*;

public class DOW {
public static void main(String [] args){
    Scanner scn = new Scanner(System.in);
    System.out.println("Enter Your Birthdate");
    System.out.print("Day : ");
    int day = scn.nextInt();
    System.out.print("Month : ");
    int month = scn.nextInt();
    System.out.print("Year : ");
    int year = scn.nextInt();
    scn.close();

    Calendar cal = Calendar.getInstance();
    cal.set(year, month-1, day);
    int dow = cal.get(Calendar.DAY_OF_WEEK);
    switch (dow){   
    case 1:
            System.out.println("Your Birthdate : " + "Sunday - " + day + "/" + month + "/" + year);
            break;
        case 2:
        System.out.println("Your Birthdate : " + "Monday - " + day + "/" + month + "/" + year);
        break;
        case 3:
        System.out.println("Your Birthdate : " + "Tuesday - " + day + "/" + month + "/" + year);
        break;
        case 4:
        System.out.println("Your Birthdate : " + "Wednesday - " + day + "/" + month + "/" + year);
        break;
        case 5:
        System.out.println("Your Birthdate : " + "Thursday - " + day + "/" + month + "/" + year);
        break;
        case 6:
        System.out.println("Your Birthdate : " + "Friday - " + day + "/" + month + "/" + year);
        break;
        case 7:
        System.out.println("Your Birthdate : " + "Saturday - " + day + "/" + month + "/" + year);
        break;
    }
}
}

but the date name in not right for example my birthdate is 18/1/1987 it's sunday the result with my code is thursday

N.B int month2 = month1-1; i write this because the months in java start with 0 not 1

so any help??

Upvotes: 1

Views: 455

Answers (4)

Basil Bourque
Basil Bourque

Reputation: 338211

The other answers are correct. But since you repeatedly asked if there is a simpler way, yes, there is.

Date-Time Library

Use a decent date-time library rather than roll your own date-time logic. Date-time work is surprisingly tricky and confusing.

But avoid the notoriously troublesome java.util.Date/.Calendar classes bundled with Java. In Java 8, those classes have been supplanted by the new java.time package. That package was inspired by the venerable Joda-Time library.

Joda-Time

Joda-Time offers a LocalDate class for when you want only a date without any time-of-day.

Here is some example code using Joda-Time 2.3.

int year = 2001;
int month = 2;
int day = 3;
LocalDate birthDate = new LocalDate( year, month, day );

DateTimeFormatter formatter = DateTimeFormat.forPattern( "'Your Birthdate : 'EEEE - d/M/yyyy" );
String output = formatter.print( birthDate );

System.out.println( output );

When run…

Your Birthdate : Saturday - 3/2/2001

Localize

Even better, a date-time library can do the work of localizing both the wording and the order.

int year = 2001;
int month = 2;
int day = 3;
LocalDate birthDate = new LocalDate( year, month, day );

java.util.Locale localeQuébécois = java.util.Locale.CANADA_FRENCH;
DateTimeFormatter formatter = DateTimeFormat.forStyle( "F-" ).withLocale( localeQuébécois );
String output = formatter.print( birthDate );

System.out.println( output );

When run…

samedi 3 février 2001

Upvotes: 1

chresse
chresse

Reputation: 5805

Its because Calender.set requires the arguments in order:

public final void set(int year, int month, int date);

and you have the wrong order. Change it to:

cal.set(year, month2, day);

and you'll get the right result.

Upvotes: 2

Federico Ponzi
Federico Ponzi

Reputation: 2775

The working code: 

import java.util.*;

public class DOW
{
    public static void main(String[] args)
    {
        Scanner scn = new Scanner(System.in);
        System.out.println("Enter Your Birthdate");
        System.out.print("Day : ");
        int day = scn.nextInt();
        System.out.print("Month : ");
        int month = scn.nextInt();
        System.out.print("Year : ");
        int year = scn.nextInt();
        scn.close();

        Calendar cal = Calendar.getInstance();
        cal.set(year, month-1, day);
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.MONDAY)
        {
            System.out.println("Your Birthdate : " + "Monday - " + day + "/" + month + "/" + year);
        }
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.TUESDAY)
        {
            System.out.println("Your Birthdate : " + "Tuesday - " + day + "/" + month + "/" + year);
        }
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.WEDNESDAY)
        {
            System.out.println("Your Birthdate : " + "Wednesday - " + day + "/" + month + "/" + year);
        }
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.THURSDAY)
        {
            System.out.println("Your Birthdate : " + "Thursday - " + day + "/" + month + "/" + year);
        }
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.FRIDAY)
        {
            System.out.println("Your Birthdate : " + "Friday - " + day + "/" + month + "/" + year);
        }
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY)
        {
            System.out.println("Your Birthdate : " + "Thursday - " + day + "/" + month + "/" + year);
        }
        if (cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY)
        {
            System.out.println("Your Birthdate : " + "Sunday - " + day + "/" + month + "/" + year);
        }
    }
}

Upvotes: 1

Am_I_Helpful
Am_I_Helpful

Reputation: 19158

I think the code has some error; cal.set(year, day, month2); must not be in this order. 

public final void set(int year,int month,int date)

is the order.

You have set it wrong,do as cal.set(year,month2,day);.

Upvotes: 1

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