Thread: error C2065: undeclared identifier PLEASE HELP!

ok so im trying to learn switch cases so i tried to write this program to see if i understood how to write them and i wrote both my variables the same exact way and its only giving me an undeclared variable for 1 of them. here's my code, please help.

Code:

#include <iostream>

using namespace std;

int main ()
{
	int a;
	int b (b = 1);
	int c (c = 2);

	for (a = 0; a < 3; a++) {
		switch (a) {
			case b:
				{
					cout<< "wow this is really confusing\n";
				}
				break;
			case c:
				{
					cout<< "now it's a little easier\n";
				}
				break;
			default:
				{
					cout<< "X-P\n";
				}
				break;
		}
	}
}

I think you mean

Code:

int b(2);

and similarly for c. Also I don't believe you can use variables in case statements, only constants.

thank you so should that part of the code look like

Code:

int a;
int b(1);
int c(2);

i tried compiling that and it said "case expression not constant." for both b and c.

whats the difference between variables and constants? sorry im a beginner haha

Variable Definition | Definition of Variable at Dictionary.com

Constant Definition | Definition of Constant at Dictionary.com

ya i know that i meant whats the difference in writing them in c++

A constant is something like 6. Or 11. Or 253. Something that is constant according to the English sense of the term.

yeah so how would i write it because when i write it like this it says "case expression not constant."

Code:

int a;
int b(1);
int c(2);

this is the whole code:

Code:

#include <iostream>

using namespace std;

int main ()
{
	int a;
	int b(1);
	int c(2);

	for (a = 0; a < 3; a++) {
		switch (a) {
			case b:
				{
					cout<< "wow this is really confusing\n";
				}
				break;
			case c:
				{
					cout<< "now it's a little easier\n";
				}
				break;
			default:
				{
					cout<< "X-P\n";
				}
				break;
		}
	}
}

ooooohhhhhh. so the case has to be a number?

thank you! it runs now! I'm sorta confused why you dont have to have "int a;" at the beginning before the loop

You do have to have int a before the loop.(*) And since you have it, everybody's happy.

(*)You are allowed to have it inside the loop itself, as in

Code:

for (int a = 0; a < 3; ++a)

all right thank you