Validating user entry not working..

[hardwired]

Hey all,

I'm using the code below and similar to validate user entry but can't seem to get it to work...

NOTE_LENGTH is declared as an integer, previously..

// GO BACK HERE IF BAD ENTRY..
DURATION_AGAIN:

cout << "Note Length (1=BAR | 2=HALF | 4=1/4th (Beat) | 8=1/8th | 16=1/16th): ";
cin >> NOTE_LENGTH;

// **************************************************
// CHECK FOR CORRECT ENTRY (NOTE LENGTH)..
// **************************************************
// IF: CHECK LENGTH OF ENTERED NOTE VALUE..
if (NOTE_LENGTH != 1 || NOTE_LENGTH != 2 || NOTE_LENGTH != 4 || NOTE_LENGTH != 8 || NOTE_LENGTH != 16 || isalpha(NOTE_LENGTH))
{
	cout << "Not a correct value.." << endl;
	goto DURATION_AGAIN;
}
// END IF.. 

What's supposed to happen is allow only 1, 2, 4, 8 or 16 to be entered. But when either one of the correct responses is entered, it passes the if and displays the cout and then with the goto, cycles round again.

When a string or alpha character is entered, the whole thing blows up. The cout msg just loops madly up and down he screen and i have to close the program.

I can't see what could be wrong with the code though, although i'm still a rookie.

Any ideas? especially a better validation technique please :)

Can i declare NOTE_LENGTH as an array like:
int NOTE_LENGTH[5] = {1,2,4,8,16};
...or something like that and have the contents as a sort of allowed entry list?

Paul..

[Moschops]

if (NOTE_LENGTH != 1 || NOTE_LENGTH != 2 || NOTE_LENGTH != 4 || NOTE_LENGTH != 8 || NOTE_LENGTH != 16 || isalpha(NOTE_LENGTH))

This will always always always come out as true. There is no value of NOTE_LENGTH for which every one of these OR'd statements comes out as false.

[hardwired]

Hey again Moschops. Oh ok, thanks. So where am i going wrong in my code / logic? How i think i'm saying it is:

If its not: 1, 2, 4, 8 or 16 or its a letter then tell them and go back round.

And I think i've got that in my code but what do i need to change?

[Moschops]

If it isn't 1, AND it isn't 2, AND it isn't 4...

[hardwired]

haha, yeah of course it is. Brilliant. So simple haha. Thanks :)

[hardwired]

Although, if a letter or character is entered, the program still goes crazy.

How can i guard against the user entering a letter? I would have thought the isalpha or !isdigit would work.

[Moschops]

https://stackoverflow.com/questions/13281669/how-do-i-sanitise-cin