PHP what that line means?

Question

I am starter php developer, I know, if else, or, elseif... but I don't understand those : ? and other symbols. So can you tell me what this lines mean:

$success = $success ? $b->save(false) : $success;

if (!success) // shouldn't this be without "!"
    $transaction->commit(); // this means "do the job, if ok"
  else
    $transaction->rollBack(); // this means "don't do the job, if not ok"

Also, can you tell me how to call this symbols, I don't know their name and so I can't find tutorials about them

This is a ternary operator, which is basically just a if else construct — Realitätsverlust, Jan 13 '14 at 12:32
@Irakli That is a terrible example for trying to learn about code; that is probably what threw you off. Success is true so rollback? Ugh. — Digital Chris, Jan 13 '14 at 12:35
@Digital Chris Yeas, I think there should be if(success) NOT if(!success) — Irakli, Jan 13 '14 at 12:36

score 4 · Accepted Answer · answered Jan 13 '14 at 12:36

It's pretty common in a lot of languages, you can find this Ternary Operations for example in javascript aswell

It is a short hand for an if/else.

The part before the ? is the condition, the next part is the code to execute if the condition returns true, and the last part (after the :) if it returns false:

condition ? if true : if false;

$a = 3 > 5 ? 'three is greater than five' : 'three is lesser than five';

In this case $a would be three is lesser than five;

I would recommend ternary operations only for very simple conditions/results, if not, you end up writting less maintainable code, sacrificing shortness for legibility

score 2 · Answer 2 · answered Jan 13 '14 at 12:34

2

the above code looks like if $success from previous transactions was true , try $b->save(false) and then put the returned value from $b->save(false) into $success.

$b->save(false) means save without validation, and after successful save, will return true

then the if part is very clear

answered Jan 13 '14 at 12:34

Developerium

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But shouldn't there be if (success) {$transaction->commit();} – Irakli Jan 13 '14 at 12:40
that makes more sense if some other stuff went ok, do the commit, but that depends on the logic previously implemented which you havn't shown us, so I can't say – Developerium Jan 13 '14 at 12:46

score 2 · Answer 3 · answered Jan 13 '14 at 12:37

2

That's a Ternary Operator, a short form for an if statement.

$success = $success ? $b->save(false) : $success;

is the same as

if($success) {
    $success = $b->save(false);
} else {
    $success = $success;
}

answered Jan 13 '14 at 12:37

Maarkoize

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PHP what that line means?

3 Answers3