php: is valid to use if/else in this way? - php

Question

Is there a way to optimize something like this?
I have already tried and it doesn't work (at least in php)
$foo = 6;
if ($foo != (3 or 5 or 10)) echo "it work";
elseif($foo < (5 or 10)) echo "it work again";
else echo "it doesn't work;"
I want to know if there's a better way to write that kind of validations.
But if something like this work in other langs, please let me know.
EDIT:
answer for this
($foo != (3 or 5 or 10)) -> in_array($foo,array(3,5,10))
does the same work if i want something like
($foo != (3 and 5 and 10))

Answer 1

No. It's not. You're testing your $foo value against the BOOLEAN result of those or operations. It'll boil down to
if ($foo != (true or true or true))
which is simply
if ($foo != true)
if (!$foo)
If you want to test a single value against multiple values, you can try
if(!in_array($foo, array(3,5,10))) { ... }
instead. For your < version, this won't work. You'll have to test each value individually:
if (($foo < 5) or ($foo < 10)) { ... }
though technically this is somewhat redundant, since if $foo is less than 5, it's already less than 10.

Answer 2

For the first you can use
if(!in_array($foo, [5,10,15]))
The second thing doesn't work in any language cause less then 5 or 10 is true for every thing less than 10. So no need for the 5. But I get your point. I don't know a fast way doing this
In python you can do this:
if(5 < x < 10)
a, b = b, a // swapping these two

Answer 3

I agree with the other answers and also, if you have more processing to do, you could also do something like this:
<?php
$x = 3;
switch ($x)
{
case 6:
$x = 5;
case 3:
case 7:
$x = 5;
case 5:
echo 'It is working' . PHP_EOL;
break;
}
EDIT: Thanks DanFromGermany for pointing the stacked cases. Added them as an example.