CODEWITHSUNDEEP
php
Joel
Joel

Reputation: 124

How you would interpret php assignment statement?

I found an example php assignment statement online which maybe resembles a tertary conditional condensed statement, but not quite. Does anyone have insight as to how to read this assignment statement?

$access = $access || $note->uid == $user->uid && user_access('note resource view own notes');

My first guess was "assign to access whatever is in access, or if empty, whether uid values are equal and'd with the return of user_access." But I get the feeling that is not correct, as it seems illogical.

Upvotes: 1

Views: 56

Answers (2)

Peter van der Wal
Peter van der Wal

Reputation: 11816

First have a look at the Operator Precedence

== comes before && comes before || comes before =

Thus your statement is more clear with adding the following parentheses:

$access = (
    $access 
    || 
    ( 
        ($note->uid == $user->uid) 
        &&
        user_access('note') 
    ) 
);

assign to access whatever is in access, or if empty,

Not quite: assign to $access the value true* when $access already evaluates to true (true, 1, "some string" etc), or

whether uid values are equal and'd with the return of user_access

Correct

And otherwise assign false. After this statement $access is always either true or false, even when $access === 'yes' before.

Note*: || and && are boolean operators, only capable of 'returning' true or false

Upvotes: 1

nitowa
nitowa

Reputation: 1107

I had this exact type of statement in a library way back, and it's basically an elaborate (or maybe just badly-styled?) null-check. Because PHP uses short circuit evaluation, the right-hand side of the or-expression will not evaluate if the left hand one was null.

Upvotes: 1

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