My if statements always return true [closed] - if-statement

Question

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Closed 10 years ago.
if ((x != A) || (x != a )|| ( x != B) || (x != b) || ( x != C) || (x != c) || (x != D) || (x != d) || ( x != F) || (x != f))
{
System.out.println("Points: -1");
return true;
}
else
{
System.out.println("hi");
return false;
}
For some reason I can't get this to return anything else but true.

Answer 1

Take the first two conditions: (x != A) || (x != a ).
What your saying here is, return true if x is either not equal to A or to a.
Assuming x == A, the first condition will return false and the second true. Thus your whole if-condition will return true.
Likewise for x == a. Here the first condition yields true and so does the if-condition.
What you probably mean is to connect all those conditions using AND or && instead of OR (||).

Answer 2

if ((x != 'A') || (x != 'a' ) ....
^ missing quotes
But even then, x can either be 'A' or 'a' or neither. With the OR evalution, you will always end up with TRUE as x will always NOT be one of those other values you are testing.
Do (x != 'A') && (x != 'a' ) ...

Answer 3

yes it will be always true
lets just concider part of your expression ((x != A) || (x != a ) ...
if x=A, then first statement is false, but other one is true, and as you have disjunction so you will always get true.
to get false you need x=A and x=a, which might be bit impossible

Answer 4

Check out this Fiddle http://jsfiddle.net/CtCqe/2/
Using regex might be better, not sure if the input of the user is only a single character or not.
Html
<div id="result">Result</div>
<input type='text'/>
<div id="pressed"></div>
Jquery
$('input').on('change input', function(){
var x = $(this).val();
if((x == 'A') || (x == 'a' )|| ( x == 'B') || (x == 'b') || ( x == 'C') || (x == 'c') || (x == 'D') || (x == 'd') || ( x == 'F') || (x == 'f')){
$('#result').html('False');
$(this).val('');
}else{
$('#result').html('True');
$(this).val('');
}
$('#pressed').html(x);
});