im wondering why i get a compiler error when i do this saying see declaration of "variable name." as far as i know i thought this was completely legal. i get a error with msvc6 when i do this:

case WM_MOUSEMOUSE:

int x = (int)LOWORD(lParam);
int y = (int)HIWORD(lParam);
  

so instead i have to declare the variable first and assign a value after which is a waste of space like this:

int x, y;
x = (int)LOWORD(lParam);
y = (int)HIWORD(lParam);
  

what am i doing wrong? [edited by - Shenron on June 22, 2002 2:50:01 AM]

You should avoid declaring variables within a case: statement, unless you actually have a { block }.

And don't worry about 'space'.

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[edited by - Fruny on June 22, 2002 2:53:53 AM]

the { and } solved it thanks a bunch

Shenron

Something to consider - if your compiler is standards compatible - those declarations go to the bit bucket as soon as the case is down. The leave scope and should vanish...


God was my co-pilot but we crashed in the mountains and I had to eat him...
Landsknecht

Landsknecht, are you sure about that? I haven''t heard of such a thing before.

That is the purpose of brackets. They define a scope. Take this for example:

for(int i = 0; i < 100; i++){   int l = 5;   FooBar(i, l);}cout << i;  // If compiler is standards compliant - this will fail, cause i has left scope...cout << l;  // This should also fail...  

P.S. And BTW - MSVC++ 6.0 is **NOT** compliant 100%. In this example, i is still valid but l will fail...

God was my co-pilot but we crashed in the mountains and I had to eat him...
Landsknecht

[edited by - landsknecht on June 22, 2002 5:40:38 AM]

Your earlier post seemed to state that a case statement should limit scope, according to the standard. Now you are explaining that braces limit scope, which I already know (I''d be worried if I didn''t).

As far as I know, a case statement is a label, and a switch statement is like a bunch of conditional gotos - and code like this should work:

quote: Original post by Landsknecht
That is the purpose of brackets. They define a scope. Take this for example:

<example omitted>

That''s an MSVC bug with for, not scope in general.

quote:
Something to consider - if your compiler is standards compatible - those declarations go to the bit bucket as soon as the case is down. The leave scope and should vanish...

case doesn''t define scope.

switch( x ){case 0:case 1:  int i;} 

The compiler complains in the above that there is a potential for the declaration of i to be skipped and asks you to wrap it in scope delimiters - curly braces.

What the...? <- referring to Beer Hunter's code.

/*=========================================*/
/* Chem0sh */
/* Lead Software Engineer & Tech Support */
/* http://www.eFaces.biz */
/*=========================================*/

[edited by - Chem0sh on June 22, 2002 2:54:55 PM]

I phrased it slightly wrong. Case may not define a scope, but a switch sure does. This does not work exactly because switch defines a scope...

int foo = 1;switch(foo){case 1:{   int bar = 5;   break;}}cout << bar << endl; 

This gives you this error:
test.cpp(17) : error C2065: ''bar'' : undeclared identifier

Tell me that is not a defined scope.


God was my co-pilot but we crashed in the mountains and I had to eat him...
Landsknecht