Initialization Error

[Always.Smile]

Hi....

This is the function:

static void sumFun (float num1, float num2) throws IOException
{
BufferedReader read = new BufferedReader( new InputStreamReader(System.in));

String strNum1, strNum2;

System.out.println("Enter the first number: ");
strNum1 = read.readLine();

System.out.println("Enter the second number: ");
strNum2 = read.readLine();

num1 = Float.parseFloat(strNum1);
num2 = Float.parseFloat(strNum2);

}

This is in the main>> switch statement>> case1:

case 1:
sumFun(num11,num22);
System.out.println("The sum of " + (num11 + num22));
break;

And I have defined these before the switch statement:

float num11, num22;

But I received this error:

variable num11 might not have been initialized
variable num22 might not have been initialized


What's the wrong??
:confused::confused:

[ojn]

Your main method has no idea what the values of num1 and num2 are.

Also, when you post code, post it all, and also use the CODE (or even better, PHP) tags, to make it more readable.

[Always.Smile]

Okay... this is my code...

import java.lang.Math;
import java.io.*;

public class TestDfunction {

static void fun(float num1, float num2) throws IOException 
    	{
    		BufferedReader read = new BufferedReader( new InputStreamReader(System.in));
		
			String strNum1, strNum2;
			
			System.out.print("Enter the first number: "); 
			strNum1 = read.readLine();
			num1 = Float.parseFloat(strNum1);
			
			System.out.print("Enter the second number: ");
			strNum2 = read.readLine();
			num2 = Float.parseFloat(strNum2);
		
    	}

  
static void menu()
{
		
		System.out.println("Please choose the type of operation needs to be computed by pressing the corresponding number: ");
		System.out.println("----------------------------------------------------------------------------------------------");		
		System.out.println("									1.		Addition");
		System.out.println("									2.		Subtraction");
		System.out.println("									3.		Multiplication");
		System.out.println("									4.		Division");
		System.out.println("									5.		Remainder");
		System.out.println("									6.		Minimum");
		System.out.println("									7.		Maximum");
		System.out.println("----------------------------------------------------------------------------------------------");	
}  	

    public static void main(String[] args)
    	
    {
    
		menu();	
		
		try{
		
		BufferedReader read = new BufferedReader( new InputStreamReader(System.in));
		
			float num11, num22;
			String strChoose;
			int choose;
			
			strChoose = read.readLine();
			choose = Integer.parseInt(strChoose);
			System.out.println("");
		
		while ((choose <1) || (choose >8))
		{
		System.out.println();
		System.out.println("The number you have entered is invalid...");
		menu();
		strChoose = read.readLine();
		choose = Integer.parseInt(strChoose);	
		}
		
		
		switch (choose)
		{	
			
		case 1: 	
			fun(num11,num22);
			System.out.println("The sum is: "+ (num11 + num22));
			break;
			
		
		case 2: 	
			fun(num11,num22);
			System.out.println("The diferrence is: " + (num11 - num22));
			break;
			
		case 3:
			fun(num11,num22);
			System.out.println("The product is: " + (num11 * num22));
			break;
		
		case 4: 	
			fun(num11,num22);
			System.out.println("The quotion is: " + (num11 / num22));
			break;

		case 5: 	
			fun(num11,num22);
			System.out.println("The remainder is: " + Math.IEEEremainder(num11,num22));
			break;
			
		case 6: 	
			fun(num11,num22);
			System.out.println("The smaller value is: " + Math.min(num11,num22));
			break;
			
		case 7: 		
			fun(num11,num22);
			System.out.println("The greater value is: " + Math.max(num11,num22));
			break;
			
		case 8:
			 System.exit(0);					
		}
		
			}		
			
		catch (IOException e) {System.out.println("IO Error");}
    	}
	}

[racerxadam]

You just need to initialize your two float variables when they are created.

float num11 = 0, num22 = 0;

[Always.Smile]

You just need to initialize your two float variables when they are created.

float num11 = 0, num22 = 0;

But then the sum is 0+0... though I passed values for num11 and num22

[ojn]

You pass num11 and num22 to fun

fun(num11,num22);

but you never assign them a value before doing so. You try to do it inside fun(), but that won't work.

You should re-read the chapters about local variables and where (and how long) they live.

[Eranga]

You should re-read the chapters about local variables and where (and how long) they live.

Yes, it must. Read more about variable declarations.

You can use any local variable before initialization. They are not automatically assign to default values. Good practice is, whatever variables you use, initialize them before use, depends on your design.

[ojn]

Hopefully this can get you on your way. You need to add a lot of stuff yourself and it can probably be done more efficient, but hey.. No one can do it all for you.

import java.util.Scanner;

public class MathProgram {
	// I prefer using the Scanner class here. Use whatever you prefer.
	private Scanner sc = new Scanner(System.in);
	
	public void menu() {
		// Prints the menu.
	}
	
	public void doTheMath() {
		/*
		 * Add try/catch and do/while blocks as you like.
		 */
		float result = 0; // Whatever the result will be.
		menu(); // Print the choices.
		int choice = // However you get an int from Scanner of BufferedReader
		/*
		 * Ask for 2 numbers here.
		 */
		switch (choice) {
		case 1:
			result = // Whatever's on option 1.
			System.out.print("The <some math thing here> is: ");
			break;
		}
		System.out.println(result);
	}
	
	public static void main(String[] args) {
		MathProgram mp = new MathProgram();
		mp.doTheMath();
	}
}