Switch Statement

[Dreamer]

Hello,

Is it possible to make a variable in, say, Case 1, recognised from, say, Case 2 in a Switch statement?

Example:

import java.io.*;

class Switch
{
	public static void main (String [] args) throws IOException
	{
		BufferedReader br = new BufferedReader (new InputStreamReader (System.in));
		String x = in.readLine ();
		int y = Integer.parseInt(x);
		switch (y)
		{
		   case 1 : {int a = 5;int b = 6;}
		   case 2 : {int c = a*b;}
		}
	}
}

In this case, the compiler complains that it cannot find variables a and b. Is there a method to solve this matter so that something declared in a case can be accessed from another one? Thanks.

[evlich]

Just put your declarations outside of the switch statement and initialize them inside. For example:

int a = 0, b = 0, c = 0;
switch (y)
		{
		   case 1 : a = 5;b = 6;
		   case 2 : c = a*b;
		}

You just have to make sure that you have good default values.

Hope this helps.

[mr1yh1]

....

[Dreamer]

Just put your declarations outside of the switch statement and initialize them inside. For example:

int a = 0, b = 0, c = 0;
switch (y)
		{
		   case 1 : a = 5;b = 6;
		   case 2 : c = a*b;
		}

You just have to make sure that you have good default values.

Hope this helps.

But if you run this code, case 2 doesn't return 30 (i.e. 5x6), it multiplies the values of a and b outside the switch statement (i.e. 0x0).

What I would like is that case 2 multiplies the values of a and b in case 1. I don't know if this is possible.

[evlich]

That is basically because of the nature of a switch statement, it is only going to execute the code that corresponds to the value that you are switching on. If you always want c to be 30 if y is 2, you just say something like c = 30. It sounds like a switch statement is not what you should be using for this, exactly what functionality are you trying to achieve?

[Dreamer]

That is basically because of the nature of a switch statement....

I thought so but wasn't sure....... thanks anyway..... I'll use some other statement.

[evlich]

What exactly is it that you are trying to do?

[mr1yh1]

But if you run this code, case 2 doesn't return 30 (i.e. 5x6), it multiplies the values of a and b outside the switch statement (i.e. 0x0).

What I would like is that case 2 multiplies the values of a and b in case 1. I don't know if this is possible.

it happens there what you want to do , if y = 1..
becos you dont use "break" statements.
be careful about it, if you dont use "break"s , it will be a error-prone code.

[Dreamer]

What exactly is it that you are trying to do?

I'm having this assignment where you have to create sort of a forum where users can choose to register or to login. So I created Case 1 for Registration and Case 2 for Login. I put no 'break' in Case 1 so that the user, after registration, goes to Case 2 to Login. Since the username was input from the user in Case 1, the function to match the username in Case 2 couldn't find the username variable since it's in Case 1.

Anyway, I managed to do it by creating blocks. Thanks.