Associate return value to a function parameter (CALL BY REFERENCE)

Question

I am wondering about returning value to a parameter instead of using =

example of "normal" way how to get return value

function dummy() {
    return false;
}

$var = dummy();

But I am looking for a method how to associate return value without using =, like preg_match_all()

function dummy($return_here) {
    return false;
}
dummy($var2);
var_dump($var2); //would output BOOLEAN(FALSE)

I am sure it has something to do with pointers but in preg_match_all() I never send any pointer to variable or am I mistaken?

preg_match_all('!\d+!', $data, $matches); // I am sending $matches here not &$matches

//I didn't know what to search for well it is simple CALL BY REFERENCE

ok, right away in doc I linked to, there is a function declaration like `int preg_match_all ( string $pattern , string $subject [, array &$matches [, int $flags = PREG_PATTERN_ORDER [, int $offset = 0 ]]] )` The most important part is `&$matches`... — Kyslik, Jan 05 '14 at 11:16

score 2 · Answer 1 · answered Jan 05 '14 at 11:17

2

Use references

i.e.

function dummy(&$return_here) {
    $return_here = false;
}
dummy($var2);
var_dump($var2);

answered Jan 05 '14 at 11:17

Ed Heal

Yes, got it myself I didn't read well the doc, answer was right there. – Kyslik Jan 05 '14 at 11:18
@Kyslik - Well accept the answer – Ed Heal Jan 05 '14 at 11:19
how greedy you are, you should know by now it is impossible to accept answer before 10 minutes mark, @second comment, exactly what I was going to do ;) – Kyslik Jan 05 '14 at 11:21

score 2 · Accepted Answer · answered Jan 05 '14 at 11:18

2

It is CALL BY REFERENCE:

function dummy(&$var) { //main difference is in this line
    $var = false;
}

dummy($var);

answered Jan 05 '14 at 11:18

Reza Mamun

For more information: http://www.php.net/manual/en/language.references.pass.php – Reza Mamun Jan 05 '14 at 11:37

2 Answers2