Need help with constructors

[tpfaff]

Edit: Added all instructions

the program is now functional but I dont think it fits the requirements of how i was supposed to do it, so if you could point me in the right direction I'd appreciate it!

Midterm Part II
Problem Statement: Month Class

Write a class named Month. The class should have an int field named monthNumber which will hold the number of the month. For example, January would be 1, February would be 2, etc. In addition, provide the following methods:

· A default constructor that sets the monthNumber field to 1.

· A constructor that accepts the number of the month as an argument. It should set the monthNumber field to the value passed as the argument. If a value less than 1 or greater than 12 is passed, the constructor should set monthNumber to 1.

· A constructor that accepts the name of the month, such as “January” , “February”, etc., as an argument. It should set the monthNumber field to the corresponding value for the month named.

· [[[ A setMonthNumber method that accepts an int argument, which is assigned to the monthNumber field.]]] If a value less than 1 or greater than 12 is passed, the method should set monthNumber to 1.

· A getMonthNumber method that returns the value in the monthNumber field.



· A toString method that returns the same value as the getMonthName method.


Class Demonstration // use default constructor, and each variation example: new Month(), new Month("March"); new Month(1);
m0 => 3:March
m1 => 2:February
m2 => 5:May
m3 => 10:October
m4 => 1:January
m5 => 11:November
m6 => 1:January
m7 => 4:April
m8 => 9:September
m9 => 1:January
m10 => 7:July
m11 => 8:August
m12 => 10:October

Month Class Demonstration //use the created Month objects to setMonthNumber() example: Month m0 = new Month("March"); m0.setMonthNumber(12);
m0 => 7:July
m1 => 5:May
m2 => 5:May
m3 => 7:July
m4 => 2:February
m5 => 1:January
m6 => 9:September
m7 => 1:January
m8 => 6:June
m9 => 3:March
m10 => 3:March
m11 => 7:July
m12 => 11:November

for the driver class...

package midtermpt2;

import java.util.Scanner;
public class MonthDriver {
   static int usernumber;
   

    public static void main(String[] args) {
        Months MonthsObj=new Months();
        getusernumber();
//        MonthsObj.Months();
        MonthsObj.setmonthNum(usernumber);
        MonthsObj.getMonthName();
    }

    public static int getusernumber(){
        Scanner input=new Scanner(System.in);
        System.out.println("Month number");
        usernumber=input.nextInt();
        return usernumber;
                
    }

}

and the other class...

public class Months {

    int monthNumber = 0;
    String monthName;

    public Months() {
        monthNumber = 1;
    }


    public int setmonthNum(int usernumber) {
        if (usernumber < 1 || usernumber > 12) {
            return monthNumber;
        } else {
            monthNumber = usernumber;
            return monthNumber;
        }//closes else
    }

    public String getMonthName() {
        switch (monthNumber) {
            case 1:
                monthName = "January";
                System.out.println(monthName);
                return monthName;
            case 2:
                monthName = "February";
                System.out.println(monthName);
                return monthName;
            case 3:
                monthName = "March";
                System.out.println(monthName);
                return monthName;
            case 4:
                monthName = "April";
                System.out.println(monthName);
                return monthName;
            case 5:
                monthName = "May";
                System.out.println(monthName);
                return monthName;
            case 6:
                monthName = "June";
                System.out.println(monthName);
                return monthName;
            case 7:
                monthName = "July";
                System.out.println(monthName);
                return monthName;
            case 8:
                monthName = "August";
                System.out.println(monthName);
                return monthName;
            case 9:
                monthName = "September";
                System.out.println(monthName);
                return monthName;
            case 10:
                monthName = "October";
                System.out.println(monthName);
                return monthName;
            case 11:
                monthName = "November";
                System.out.println(monthName);
                return monthName;
            case 12:
                monthName = "December";
                System.out.println(monthName);
                return monthName;
            default:
                System.out.println("invalid number");
                return monthName;
        }
    }
}//close class

So now I dont get what hes asking in the bolded type. Which way of doing it am I demonstrating with the above program?

[tpfaff]

ok so now im reading over it again and the terminology is really confusing me but im pretty sure when it says an int field it means to make an array named monthnumber and have it go 0-11

[j2me64]

constructors have no return values, not even void. so delete void from your constructors.

[Zack]

There's a few issues here:

First, what j2me mentioned: Don't assign a return type to the constructor--simply "public Months() {". Also, don't return a value. (See Understanding constructors - JavaWorld.)

Second, you should be trying to hold a single integer value in the variable monthNumber; you are storing an array. (Read the first bit of your assignment: Write a class named Month. The class should have an int field named monthNumber.. Note that it says int, not int[].)

Third, when it says to "sets the monthNumber field to", it means to assign a value to that variable. Take a look at the line "usernumber=input.nextInt();"--this is an example of setting a value to a variable.

Let's start by fixing those--we'll get to the rest of the project in a bit.

[tpfaff]

Second, you should be trying to hold a single integer value in the variable monthNumber; you are storing an array. (Read the first bit of your assignment: Write a class named Month. The class should have an int field named monthNumber.. Note that it says int, not int[].)


Wouldnt it seem better to do it the way I did it? I understand that thats not what its asking me to do but I'm a little confused as to why he'd want us to do it that way

[Norm]

int monthNumber[]={0,1,2,3,4,5,6,7,8,9,10,11,12};
In this array, the value is the same as the index to the value.
For example: monthNumber[2] = 2;

The array is redundant.

[tpfaff]

ah, haha that makes sense, so itd be better to just put [12] instead of listing them all right?

[Zack]

No, it would be better to just make it an int field, as your project suggests.

int monthNumber = 0;

Then set its initial value in your constructor.

[tpfaff]

Somebody pmed me and asked for the final code

I didn't ever figure out how to compare two objects, my teacher showed me how but I don't have his version only mine. I would still like to know if someone wants to show me ;)

Driver class

package part2;

public class MonthDriver {

    public static void main(String[] args) {
        System.out.println("Constructor demo");
        Months m0 = new Months("MARCH");//accessing non default string constructor
        //looks for enum march, does what it says in there. Same for all 13 objects
        m0 = new Months(3);//accessing non default int constructor, does what is says at case 3. Same for all 13 objects.
        Months m1 = new Months("FEBRUARY");
        m1 = new Months(2);
        Months m2 = new Months("MAY");
        m2 = new Months(5);
        Months m3 = new Months("OCTOBER");
        m3 = new Months(10);
        Months m4 = new Months("JANUARY");
        m4 = new Months(1);
        Months m5 = new Months("NOVEMBER");
        m5 = new Months(11);
        Months m6 = new Months("JANUARY");
        m6 = new Months(1);
        Months m7 = new Months("APRIL");
        m7 = new Months(4);
        Months m8 = new Months("SEPTEMBER");
        m8 = new Months(9);
        Months m9 = new Months("JANUARY");
        m9 = new Months(1);
        Months m10 = new Months("JULY");
        m10 = new Months(4);
        Months m11 = new Months("AUGUST");
        m11 = new Months(6);
        Months m12 = new Months("OCTOBER");
        m12 = new Months(10);
        System.out.println();

        System.out.println("Month Class Demonstration");

        m0.setmonthNum(7);//sets month number to 7
        m0.getoMonthNumber();//returns month number
        m0.getMonthName();//gets the month name based on themonthNumber;
        m0.print();//prints monthnumber
        m0.toString();//prints monthname and returns it as a string
        //same steps for all 13 objects
        
        m1.setmonthNum(5);
        m1.getoMonthNumber();
        m1.getMonthName();
        m1.print();
        m1.toString();
        
        m2.setmonthNum(5);
        m2.getoMonthNumber();
        m2.getMonthName();
        m2.print();
        m2.toString();
        
        m3.setmonthNum(7);
        m3.getoMonthNumber();
        m3.getMonthName();
        m3.print();
        m3.toString();
        
        m4.setmonthNum(2);
        m4.getoMonthNumber();
        m4.getMonthName();
        m4.print();
        m4.toString();
        
        m5.setmonthNum(1);
        m5.getoMonthNumber();
        m5.getMonthName();
        m5.print();
        m5.toString();
        
        m6.setmonthNum(9);
        m6.getoMonthNumber();
        m6.getMonthName();
        m6.print();
        m6.toString();

        
        m7.setmonthNum(1);
        m7.getoMonthNumber();
        m7.getMonthName();
        m7.print();
        m7.toString();

        m8.setmonthNum(6);
        m8.getoMonthNumber();
        m8.getMonthName();
        m8.print();
        m8.toString();
        
        m9.setmonthNum(3);
        m9.getoMonthNumber();
        m9.getMonthName();
        m9.print();
        m9.toString();
        
        m10.setmonthNum(3);
        m10.getoMonthNumber();
        m10.getMonthName();
        m10.print();
        m10.toString();
        
        m11.setmonthNum(7);
        m11.getoMonthNumber();
        m11.getMonthName();
        m11.print();
        m11.toString();
        
        m12.setmonthNum(11);
        m12.getoMonthNumber();
        m12.getMonthName();
        m12.print();
        m12.toString();

        System.out.println();
        System.out.println("greater than less than equal to comparison");
        System.out.println();
//        System.out.println("m0="+m0.setmonthNum(7)+" m1="+m1.setmonthNum(5));//
        System.out.println(""+m0+m1);// the objects are set to string values and I cant figure out why
        m1.equals(m0, m1);//none of these work correctly
        m1.lessThan(m1, m0);
        m1.greaterThan(m1, m0);

    }
}

package part2;

public class Months {

    public int monthNumber;
    public String monthName;
    public int oMonthNumber;

    enum Spectrum {//declares the values that are going to be used in the enum

        JANUARY, FEBRUARY, MARCH, APRIL, MAY, JUNE, JULY,
        AUGUST, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER
    }

    public Months() {
        monthNumber = 1;
    }

    public  Months(int monthNumber2) {//sets monthname from the objects int value and prints month name
        switch (monthNumber2) {
            case 1:
                monthName="January";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 2:
                monthName="February";
                System.out.println(":"+monthName);
               //sets monthname from the objects int value and prints month name
                break;
            case 3:
                monthName="March";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 4:
                monthName="April";
                System.out.println(":"+monthName);
               //sets monthname from the objects int value and prints month name
                break;
            case 5:
                monthName="May";
                System.out.println(":"+monthName);
               //sets monthname from the objects int value and prints month name
                break;
            case 6:
                monthName="June";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 7:
                monthName="July";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 8:
                monthName="August";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 9:
                monthName="September";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 10:
                monthName="October";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 11:
                monthName="November";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            case 12:
                monthName="December";
                System.out.println(":"+monthName);
                //sets monthname from the objects int value and prints month name
                break;
            default:
                System.out.println("invalid number");
                                break;
        }

    }

    public Months(String monthname) {
//        A constructor that accepts the name of the month, such as “January” ,
//                “February”, etc., as an argument. It should set the monthNumber
//                field to the corresponding value for the month named.
//        monthname=null;
        Spectrum month;
        month = Spectrum.valueOf(monthname);
        switch (month) {
            case JANUARY:
                monthNumber = 1;
                System.out.print(monthNumber);
                break;
            case FEBRUARY:
                monthNumber = 2;
                System.out.print(monthNumber);
                break;
            case MARCH:
                monthNumber = 3;
                System.out.print(monthNumber);
                break;
            case APRIL:
                monthNumber = 4;
                System.out.print(monthNumber);
                break;
            case MAY:
                monthNumber = 5;
                System.out.print(monthNumber);
                break;
            case JUNE:
                monthNumber = 6;
                System.out.print(monthNumber);
                break;
            case JULY:
                monthNumber = 7;
                System.out.print(monthNumber);
                break;
            case AUGUST:
                monthNumber = 8;
                System.out.print(monthNumber);
                break;
            case SEPTEMBER:
                monthNumber = 9;
                System.out.print(monthNumber);
                break;
            case OCTOBER:
                monthNumber = 10;
                System.out.print(monthNumber);
                break;
            case NOVEMBER:
                monthNumber = 11;
                System.out.print(monthNumber);
                break;
            case DECEMBER:
                monthNumber = 12;
                System.out.print(monthNumber);
                break;
            default://fix later
                System.out.println("Month number 1");
                monthNumber = 1;
                monthname = "HELLO";
                break;
        }
    }

    public void setmonthNum(int monthNumber2) {
 switch (monthNumber2) {
          
            case 1:
                monthNumber=1;
                break;


            case 2:
                monthNumber=2;
                break;

            case 3:
                monthNumber=3;
                break;

            case 4:
                monthNumber=4;
                break;

            case 5:
                monthNumber=5;
                break;

            case 6:
                monthNumber=6;
                break;

            case 7:
                monthNumber=7;
                break;

            case 8:
                monthNumber=8;
                break;

            case 9:
                monthNumber=9;
                break;

            case 10:
                monthNumber=10;
                break;

            case 11:
                monthNumber=11;
                break;

            case 12:
                monthNumber=12;
                break;

        
            default:
                monthNumber=1;
                break;

    }
    }

    public void print() {
        System.out.print(monthNumber);
    }

    public int getoMonthNumber() {
        this.monthNumber = monthNumber;
        return monthNumber;

    }

    public int getMonthName() {
     switch (monthNumber) {
            case 1:
                monthName = "January";//the objects are making themselves equal to these strings and I dont know why.
                monthNumber = 1;
                return monthNumber;

            case 2:
                monthName = "February";
                monthNumber = 2;
                return monthNumber;
            case 3:
                monthName = "March";
                monthNumber = 3;
               
                return monthNumber;
            case 4:
                monthName = "April";
                monthNumber = 4;
               
                return monthNumber;
            case 5:
                monthName = "May";
                monthNumber = 5;
                
                return monthNumber;
            case 6:
                monthName = "June";
                monthNumber = 6;
                
                return monthNumber;
            case 7:
                monthName = "July";
                monthNumber = 7;
                
                return monthNumber;
            case 8:
                monthName = "August";
                monthNumber = 8;
                
                return monthNumber;
            case 9:
                monthName = "September";
                monthNumber = 9;
                
               return monthNumber;
            case 10:
                monthName = "October";
                monthNumber = 10;
                
                return monthNumber;
            case 11:
                monthName = "November";
                monthNumber = 11;
               
                return monthNumber;
            case 12:
                monthName = "December";
                monthNumber = 12;
                
                return monthNumber;
            default:
                System.out.println("invalid number");
                return monthNumber;
        }
    }


    public String toString() {
        System.out.println(":" + monthName);
        return monthName.toString();
    }

    public boolean equals(Months m0, Months m1) {
        if (m0 == m1) {
            System.out.println("m0==m1");
            return true;
        } else {
            System.out.println("mo!=m1");
            return false;
        }

    }


        //returns true if the first object is greater than the second
    }//close class

[DarrylBurke]

Somebody pmed me and asked for the final code

I would report abuse for that. Technical questions should be kept on the forum. A PM suggests a homework moocher.

db

[tpfaff]

:eek::eek::eek: