iif Function - what's using for ?

[Creative Suite]

well , i want to have any easy example with explaining for ( iif ) function , please :)

regards ;)

[Xenon]

for asigning variables?

as an example
$navbar = iif(isloggedin(), fetch_user_nav(), fetch_guest_nav());

it can just speed up processes :)

[Andreas]

It's "a shortcut" for

if (isLoggedin()) {
$navbar = fetch_user_nav();
} else {
$navbar = fetch_guest_nav();
}


Or in other words

$navbar = isLoggedin() ? fetch_user_nav() : fetch_guest_nav();

[Creative Suite]

Xenon & KirbyDE

thanks , i understood it :)

regards :classic:

[Xenon]

you're welcome :)

[sabret00the]

i think it's official name is inline if conditional, not sure though :)

[Marco van Herwaarden]

aka Inline If

[Xenon]

Insert If?

:D

[Jolten]

Terniary operator I believe.

[Xenon]

yep, that's the general terminus for the ? : construct

[WetWired]

Does PHP not directly support ?: ?

[sabret00the]

it does but the IIF's are purdier ;)

[Andreas]

Does PHP not directly support ?: ?
It does. iif() is just a wrapper.

[filburt1]

In iif(), the third argument is optional, which can make it more convenient every now and then.

[Xenon]

not that i ever needed that special behaviour of iif ;)

[deathemperor]

iff() is really useful when used within queries, it's such a simple but effective functions. Vb staffs always do great jobs.

[sabret00the]

isn't IIF actually a php function?

guess not, i've been using it all this time and didn't even know lol

[Andreas]

No, it's a vBulletin function defined in functions.php

[deathemperor]

isn't IIF actually a php function?

guess not, i've been using it all this time and didn't even know lol
that's really funny, guess you use editor with non color highlight ? if DW or any other that highlight php functions they won't do in iff(), simple it's not a php based

[sabret00the]

that's really funny, guess you use editor with non color highlight ? if DW or any other that highlight php functions they won't do in iff(), simple it's not a php based
you know what, i've only just realised that it don't highlight the iif() in the red it uses for other functions. damn. lol

[Dean C]

The function is kind of redundant, the only time it helps is with clarity for new coders. I just tend to use in my scripts :)


$var = $arewetrue ? 'yes' : 'no';

[Brad]

No, it's a vBulletin function defined in functions.php
Heres the code for it if anyone dos'nt want to go searching.

From functions.php

// ###################### Start iif #######################
function iif($expression, $returntrue, $returnfalse = '')
{
return ($expression ? $returntrue : $returnfalse);
}

[Xenon]

actually my editor highlights it as well, as i'm highlighting some vb functions ^^

[noppid]

iif() is handy for true and false returns. However if you use it to test and then pass data, if the data chunk is large, it may be much more inefficent then a plain old if/else.

[filburt1]

I did just notice one major problem with it, but it's the design of PHP (and most other languages) that causes it: the ternary operator supports lazy evaluation (only evaluates what is needed based on the condition), whereas the iif() function evaluates all of its arguments regardless of the condition's value.

An excerpt of my code that demonstrates the problem:

function vbms_get_all_quota_usages($userids = false)
{
global $DB_site;

$usages = array();
$extrawhere = iif($userids !== false, "AND userid IN (" . implode(", ", $userids) . ")");

Look at that last line. If $userids strictly equals false, it will still try to implode $userids, and of course you can't implode a non-array. The ternary operator's lazy execution doesn't try to implode $userids if it is boolean false.

[noppid]

Ah yes and here's the example I had written and realized the overhead it created just moving a copy of the data, I overlooked that it executed the addslashes() function as well even if it was not needed.

This is very inefficient, in some cases $data could have been 1MB...



iif($vbg_use_fs, '', addslashes($data));



Nice tip filburt.

[deathemperor]

as the name of the varibles vb defined, this is absolutely useful for boolean vale the best.