define variable within conditional whilst testing against in php - php

Question

Is it possible to call a method within a conditional to test against but also store return in a var within the same conditional reducing the api calls?
ie something like this:
elseif(
($auth_type = \proj101\user::getUserAuthType( $user_profile['email'] ) )
&& $auth_type != AUTH_TYPE_GOOGLE
){
//$auth_type now equals the function return and not just 'true'

Answer 1

Yeah, you can do that, you just have to get the order of operations right. Since assignment has lower precedence than logical &&, you end up setting auth_type to the result of the && operation.
Consider this simple example:
<?php
const AUTH_TYPE_GOOGLE = 1;
function userAuthTypeStub( $x ){
return 2;
}
if( 0 ){
// who knows what to do?
}
elseif(
$auth_type = userAuthTypeStub( 0 )
&& $auth_type != AUTH_TYPE_GOOGLE
){
echo "$auth_type\n" . userAuthTypeStub(0) . "\n";
}
you get
1
2
but if you fix the order of operations, you get what you expect:
<?php
const AUTH_TYPE_GOOGLE = 1;
function userAuthTypeStub( $x ){
return 2;
}
if( 0 ){
// who knows what to do?
}
elseif(
( $auth_type = userAuthTypeStub( 0 ) )
&& ( $auth_type != AUTH_TYPE_GOOGLE )
){
echo "$auth_type\n" . userAuthTypeStub(0) . "\n";
}
2
2
Note I had to adjust the result of the function in both cases, because if $auth_type ends up being 0 in either case, the elseif evaluates to false and the output is never executed. That's one of the reasons I agree with most of the criticisms being offered that it would make the most sense to set $auth_type and then test its value.
Some languages (namely: C, if I'm not mistaken) don't promise anything about the order of operations of both sides of a logical &&, so it may be safe to say that depending on the second from the first is a bad practice. I think that may be for the optimizations possibly gained by reversing the order. This certainly isn't C so maybe it doesn't matter, but it sure makes debugging harder!
http://www.php.net/manual/en/language.operators.precedence.php