if statement not working right?

Question

I've looked and looked with the debugger and cannot seem to figure out why the IF statement always prints the message.

The IF statement checks to see if yesno != 'Y' ||(or) 'N' but regardless if i type y or Y or n N or H B it will show... . Im not sure what move to make anymore! I cant seem to find where its going wrong?

if(yesno != 'Y' || 'N') { ...

Thanks guys.

Answer 1

The || doesn't quite mean what you think it means. The correct approach is:

if (yesno != 'Y' && yesno != 'N') { ...

This evaluates each side of the && independently, and the result is true if both sides are true.

Note that

if (yesno != 'Y' || yesno != 'N') { ...

will always be true because any given character is either not Y or it is not N. This is probably not what you want.

Answer 2

You need to put

if (yesno != 'Y' || yesno != 'N')

You always need to put the full expression twice.

Answer 3

you cannot OR an expression (yesno!='Y') and a statement ("N") which is also an expression. its only two or more expressions that can be combined using || and && to get the required output.

if(yesno!="Y"||"N")

is actually

if(yesno!="Y" || TRUE)

which is always true because:

Exp||TRUE=TRUE 

regardless of the expression.

use if(yesno!="Y"|| yesno!="N")      // and in this case its && and not || i think

Answer 4

if(yesno != 'Y' || 'N')

should be:

if(yesno != 'Y' && yesno != 'N')

You are chaining them which is incorrect. I am fairly sure you know that you should not and that is a typo, because you used && correctly on line no 44.

Answer 5

Take the conditional yesno != 'Y' || 'N' apart. It has two clauses:

1. yesno != 'Y'. This is probably a comparison you intended; it checks to see if the char yesno is inequal to the value 'Y'.
2. 'N'. This clause evaluates simply to the value 'N'. As a bool, 'N', which is not zero, is considered "true."

So you have "(stuff) || (always true)". Here "stuff" is yesno != 'Y' and "always true" is 'N'. The result will always be true.