PHP IF statement

[Manat]

Hello all

I have an if statement and want to add an OR

if ($referer != "http://www.somewhere.com/hello.html")
{ }

How do I add an AND to the above?
Like this:

if ($referer != "http://www.somewhere.com/hello.html" || "http://www.somewhere.com/hello.html?something=adfa")

Is there any other better way to do this?
Thx

[BeastRider]

When negating a comparison, the 'or's become 'and's as in

if (($referer != "http://www.somewhere.com/hello.html")
  && ($referer !=  "http://www.somewhere.com/hello.html"))
  {
  // do some stuff if not one of the unwanted referrers
  }

[stolzyboy]

if ($referer != "http://www.somewhere.com/hello.html" || $referer != "http://www.somewhere.com/hello.html?something=adfa")

[BeastRider]

Originally posted by stolzyboy

if ($referer != "http://www.somewhere.com/hello.html" || $referer != "http://www.somewhere.com/hello.html?something=adfa")

[/B]

That won't work. Let's say that $referer is indeed not equal to the first tested value. Execution of the test will end because you 'or'ed the tests together. But you still might have a URL you don't want only it is further down the test list. Got to use &&

[stolzyboy]

doh, didn't notice the !=, it would work if he used == in that sense

[Manat]

Eh?

Are you guys sure?

if ($referer != "http://www.somewhere.com/hello.html" || $referer != "http://www.somewhere.com/hello.html?something=adfa")

If I use the OR ||, doesn't that mean if first condition not met then check second?

If I use AND &&, then doesn't that mean that in order for the logic within that IF{}not to get executed, the user would have to have both URLs in his address bar, which is impossible? Both conditions would have to be met, which isn't possible, no?

Wouldn't I have to use the || OR, if first condition met, ok to this, if first condition not met, but second condition is met, then do this, if both conditions not met, ok go to Else.

Sorry guys, i'm a little confused as to why I would use the && where no one would have both URLs in their address bar.

Thx
MK

[BeastRider]

OK... let's say I want to execute the if statement only if I don't have an 'A' or 'B' or 'C' or 'D'. Then

$wort = 'C'
// using an OR
if (($wort != 'A')  // this condition is true
  || ($wort != 'B') // also true
  || ($wort != 'C') // false
  || ($wort != 'D')) // this is true
  {
  // this will be executed because at least one of the conditions tested 
  // true and you have written the statement such that if any of the 
  // conditions test true then the statement will be executed
  }

Now, when done with an AND

$wort = 'C'
// using an OR
if (($wort != 'A')  // this condition is true
  && ($wort != 'B') // also true
  && ($wort != 'C') // false
  && ($wort != 'D')) // this is true
  {
  // this will NOT be executed because the AND requires that all conditions 
  // be true and clearly there is one false condition.    

  }

This is a point of confusion for many new (and not so new) programmers. When negating a test OR's must become AND's.

[stolzyboy]

beast is very correct, hence the negating, but if you did the same thing with ||'s and using ==, your results will be different, almost exactly opposite, you just need to think kinda backwards when using != and ||'s, it is a little confusing at first but you will get the hang of it in time

take this for example with the "=="

<?
//$tester = "beast";
//$tester = "rider";
$tester = "stolzyboy";
if ($tester == "beast" || $tester == "rider")
{
echo "You can be here ";
}
else
{
echo "You can't be here ";
}
echo $tester;
?>