Help with C++ loop

[Spev]

I'm trying to make a condition be met with both while loops, and do while loops. Here's an example:

 

while (variable != 'A')

{

CODE

}

 

^^^ This would only be run if the char variable is not equal to capitol A. I have touppered all of my chars for this code, so the upper case is not causing issues. This code works great. However....I'm trying to run this but I want to add 3 other letters to the mix. For example:

 

while ((variable != 'A') || (variable != 'B') || (variable != 'C') || (variable != 'D'))

{

CODE

}

 

^^^So this should only be ran if "variable" is NOT equal to the char A, B, C, or D. I tested this in a while loop, even when variable was equal to A (couted to check) it STILL ran the code. Additionally, I need a similar statement at the end of a do while loop. In the do while loop, I want the code to repeat ONLY if variable != A, B, C, or D. Even when variable was equal to A it still ran the code(a second time to be clear, since it's a do while, will always run once)...........what the hell, someone please help? I've never had such an issue with while/do while loops before...EVER.

[79wjd]

Lets assume variable=A.

 

Then when you get to the second loop, you evaluate the conditions. Does Variable=A? Yes, go to the next condition. Does Variable=B? No, enter the loop and execute the code. So you need to change the logic of the while loop. 

[DXMember]

 

	while (variable != 'A')
	{
	//CODE
	}
	 
	// variable can't be A, B, C and D at the same time, when you do logical OR on those conditions
	// you always get True,
	// because if the variable is 'A' then it's not 'B' so the condition is true
	// You have to make sure the variable is none of those values at the same time
	while ((variable != 'A') && (variable != 'B') && (variable != 'C') && (variable != 'D'))
	{
	//CODE
	}
	

Here's a great article explaining the difference between Logical AND and Logical OR operators

https://msdn.microsoft.com/en-us/library/z68fx2f1.aspx

 

[Unimportant]

while ( (Variable < 'A') || (Variable > 'D') )
{
  	//CODE
}

This will work better for a large range in stead of testing each possibility manually.