can i shorten some php like this?

SooTyLaD · 10 Sep 2008 at 08:45

quick question: can i use something similar to this shortened code:

Code:

if (strpos($fname, "p.jpg"|"t.jpg") > 0){

or does it have to be more like:

Code:

if ((strpos($fname, "p.jpg") > 0) | (strpos($fname, "t.jpg") > 0){

?

funny thing is the first one seems to work but only acknowledges the filenames ending in t not p :confused:

Ladforce · 10 Sep 2008 at 09:54

cant you just add the strings? Also you cant compare to 0 as fname could occur at position 0. use === false to determine the outcome.

Code:

if (strpos($fname, "p.jpg"."t.jpg") > 0){

Inquisitor · 10 Sep 2008 at 10:14

SooTyLaD said:
quick question: can i use something similar to this shortened code:

Code:

if (strpos($fname, "p.jpg"|"t.jpg") > 0){

No; what you're actually doing there is taking the bitwise OR of those two strings, converting it back to a string, and then using the result. This won't work as expected

Try using a regular expression instead:

Code:

if (preg_match('/p.jpg|t.jpg/i', $fname))
{
	// Stuff…
}

Note that this will me marginally slower than using strpos twice.

Ladforce said:
cant you just add the strings? Also you cant compare to 0 as fname could occur at position 0. use === false to determine the outcome.

Code:

if (strpos($fname, "p.jpg"."t.jpg") > 0){

That won't work as it'll test if they're both present in the string in succession.

Ladforce · 10 Sep 2008 at 10:18

Sorry your right, I got the parameter order wrong, thought we were searching in p.jpg t.jpg not for it.

Inquisitor · 10 Sep 2008 at 10:20

Ladforce said:
Sorry your right, I got the parameter order wrong, thought we were searching in p.jpg t.jpg not for it.

That's PHP for you: horribly inconsistent function naming and parameter ordering throughout the standard library!

Edit: it's probably also worth mentioning that you shouldn't use a single pipe (|) or ampersand (&) for logical operations; instead use double pipes and ampersands: || and &&. The reason for this is that || and && are what are called short circuit operators – that is, they only evaluate their operands as necessary.

For example: when evaluating ($foo || $bar), then if $foo is true, $bar won't be evaluated (since whatever it is the outcome will still be true). The converse is true for &&.

This can be useful in a scenario where the second operand can only be evaluated if the first is true, for example:

Code:

if ($foo != null && $foo->bar())
{
	// Stuff…
}

If you were to use & in this case, then $foo->bar() would be evaluated even if $foo is null, which would cause a fatal error.

By contrast, | and & are bitwise operators, which are actually meant for manipulating individual bits in binary values. See:
http://uk2.php.net/language.operators.bitwise

SooTyLaD · 10 Sep 2008 at 13:01

all very good to know

the regex method above worked great

could you tell me the purpose of the slashes either side of the expression?

/p.jpg|t.jpg/i

Inquisitor · 10 Sep 2008 at 13:05

They're just delimiters that mark the beginning and end of the expression itself; anything outside the delimiters is interpreted as a modifier. The i modifier there makes it a case-insensitive match. You don't have to use forward slashes; you can use whatever symbol you like (as long as you escape it when it occurs in the expression).

I'd recommend reading up on regexes; they're awesomely powerful, if a little complex at first glance:
http://uk.php.net/manual/en/regexp.reference.php

Shoseki · 10 Sep 2008 at 13:29

Another thumbs up for regexes from me - even if I can't use them properly yet, I recognise their potential!

Dj_Jestar · 10 Sep 2008 at 13:40

Inquisitor said:
That's PHP for you: horribly inconsistent function naming and parameter ordering throughout the standard library!

This attitude to PHP makes me laugh. Wasn't it PHP that you used to learn pretty much everything you know? Or at least put into practice?

It may also just be me, but I've only noticed .NET'ers "whinge" about PHP.. no one else does.

Inquisitor · 10 Sep 2008 at 14:06

Dj_Jestar said:
Wasn't it PHP that you used to learn pretty much everything you know? Or at least put into practice?

Not really, but then at no point did I say it's not a useful or effective language, either. Ineed I very much prefer PHP to ASP.NET for web development.

Dj_Jestar said:
It may also just be me, but I've only noticed .NET'ers "whinge" about PHP.. no one else does.

I think it's just you.

ChrisB · 10 Sep 2008 at 14:23

Inquisitor said:
I think it's just you.

Nope I actually agree with him

Inquisitor · 10 Sep 2008 at 14:45

ChrisB said:
Nope I actually agree with him

OK well I have to say it's not something I've ever noticed. In my experience, most of the PHP hate comes from people using languages similar in market/purpose like Ruby and Python. .NET and PHP serve completely different purposes.

I have to say I do miss a lot of the features from .NET when using PHP, though.

LazyManc · 12 Sep 2008 at 10:31

PHP is my bread and butter but the inconsistencies are definitely an annoyance...

strpos vs str_replace - why do some string function names have underscores and others do not?

strpos($haystack, $needle)
vs
in_array($needle, $haystack)

It's not something that will stop me using PHP, it's just one of the quirks of the language, but it would have been nice if for v6 they thought "sod backwards compatibility" and tidied it up.