Can anyone see the problem in this code??

LanceStorm

Can anyone see this problem?
The program takes in two numbers, gives a menu, the user selects an option, then the program calls the function, does the calculation and prints it on screen.
Problem is, it keeps displaying the calculation over and over in a loop for some reason, I cant see the problem?!
Any help greatly appriciated!!

---

//Project Program
class num{

//Declaring variables
static final double pi = 3.1416;
private int num1;
private int num2;

//Constructor
public num(int a, int b)
{
num1 = a;
num2 = b;
}


//Add Function
public void add()
{
Screen.newline();
Screen.cursorpos(35);
Screen.writeInt(num1);
Screen.message(" + ");
Screen.writeInt(num2);
Screen.message(" = ");
Screen.writeInt(num1+num2);
}

//Subtract Function
public void subtract()
{
Screen.newline();
Screen.cursorpos(35);
Screen.writeInt(num1);
Screen.message(" - ");
Screen.writeInt(num2);
Screen.message(" = ");
Screen.writeInt(num1-num2);
}
//Divion Function
public void divide()
{
Screen.newline();
Screen.cursorpos(35);
Screen.writeInt(num1);
Screen.message(" / ");
Screen.writeInt(num2);
Screen.message(" = ");
Screen.writeInt(num1/num2);
Screen.message(" . ");
Screen.writeInt(num1%num2);
}
//multiplication Function
public void multiply()
{
Screen.newline();
Screen.cursorpos(35);
Screen.writeInt(num1);
Screen.message(" * ");
Screen.writeInt(num2);
Screen.message(" = ");
Screen.writeInt(num1*num2);
}

//area Function
public void area()
{
Screen.newline();
Screen.cursorpos(35);
Screen.message(" Area = ");
Screen.writeDouble(pi*num1*num1);
}

//volume Function
public void volume()
{
Screen.newline();
Screen.cursorpos(35);
Screen.message(" Volume = ");
Screen.writeDouble(4*pi*(num1*num1*num1)/3);
}

//Circumference Function
public void Circumference()
{
Screen.newline();
Screen.cursorpos(35);
Screen.message(" Circumference = ");
Screen.writeDouble(pi*num1);
}


//Menu Options
public int call()
{
int opt1;

//Telling user the options
Screen.newline(2);
Screen.message("********************************************************************************");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 1: Add Variables -> Press 1 for Addition");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 2: Subtract Variables -> Press 2 for Subtraction");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 3: Divide Variables -> Press 3 for Division");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 4: Multiply Variables -> Press 4 for mulitiplication");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 5: Area of circle -> Press 5 to find area of a circle");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 6: Volume of circle -> Press 6 to find volume of a circle");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 7: Circumference of circle -> Press 7 to find Circumference of a circle");

Screen.newline(2);
Screen.cursorpos(2);
Screen.message("Option 9:Exit program -> Press 9 to exit");

Screen.newline(2);
Screen.message("********************************************************************************");

//statement to acknowlage user selection
Screen.cursorpos(30);
Screen.message("Option selected = ");
opt1 = Keyboard.readInt();
return opt1;

}

}

---

//Test Program
class numTest
{
public static void main(String[] args)
{

//Declaring Variables
int a;
int b;
int opt1;

//asking user to enter values into variables
Screen.cursorpos(30);
Screen.message("Enter two numbers");
Screen.newline(2);
Screen.message(" Number 1 will count as radius and diameter in option 5, 6 and 7 respectively");

//reading in numbers to variable
Screen.newline(2);
Screen.cursorpos(35);
a = Keyboard.readInt();
Screen.cursorpos(35);
b = Keyboard.readInt();


//creating instance
num result1 = new num(a,b);

//value returned from the call function & stored in opt1
opt1 = result1.call();

//Exit Function
while(opt1 !=9)
{
//IF function for menu
if (opt1== 1)
{
result1.add();
}
else if (opt1== 2)
{
result1.subtract();
}
else if (opt1== 3)
{
result1.divide();
}
else if (opt1== 4)
{
result1.multiply();
}
else if (opt1== 5)
{
result1.area();
}
else if (opt1== 6)
{
result1.volume();
}
else if (opt1== 7)
{
result1.Circumference();
}

}
}
}

seamus

What language is that?

Looks like C++, but using some extra classes

LanceStorm

Oh sorry forgot to mention that vital factor!!
Its Java!

LanceStorm

And Pat Patterson is always funny!!

Obscure

Looks like problem here:


//value returned from the call function & stored in opt1
opt1 = result1.call();

//Exit Function
while(opt1 !=9)
{
// stuff
}


... so if set "opt1" to 1 lets say, then while statement will go check over and over if "opt1 != 9" and it never is so "//stuff" will be executed over and over ad infiniam (?).

maybe something like:

//value returned from the call function & stored in
opt1 = result1.call();

//Exit Function
while(opt1 !=9)
{
// stuff

opt1 = result1.call();
}


is required.

Ob

OfflerCrocGod

A) Have you ever used System.out.println("String");?, if so USE IT.
Do not use Keyboard unless you understand what its doing, you are doing a disservice to your self if you dont learn how to use BufferReader.
C) I believe while(opt1 !=9) is to blame, its just testing opt1 over and over again but opt1 is the same number its never changed, give the user a choice to change it, put the while to encompass PRACTICALLY all of the main method except for the int opt1; part which should be int opt1=0; that way it keeps looping the question to the user asking for more input until it gets a nine.

OfflerCrocGod

Or what Obscure says, although that means that nothing will be printed from the main class.

LanceStorm

Thank You Obscure!!
You are a legend!!

It works perfectly now!!

Cannot thank you enough!!
No longer gonna fail my programming presentation cuz of you!!

Trojan

All: please post code samples in [ code ] tags in order to maintain readability - makes things all that easier to debug.

Cheers,
Al.

Cake Fiend

Is there no equivalent to a switch statement in Java?

seamus

Originally posted by Sico
Is there no equivalent to a switch statement in Java?

There is a switch. Almost exactly the same as a C switch IIRC.