Is there garbage collection in PHP?

Question

I know that in PHP you don\'t have to free memory. Is it reached by garbage collector?

Answer 1

Yes. There is also session cleanup done by the garbage collector.

Answer 2

PHP has a combination of garbage collection and reference counting. The latter is the main mode of managing memory, with the garbage collector picking up the pieces that the ref counter misses (circular references). Before 5.3, php only had ref-counting, and even in 5.3 it's the still how memory will usually be freed.

Answer 3

Since 5.3.0 you can force garbage collection by using gc_collect_cycles function.

Answer 4

since 5.3.0 there is garbage collection support. please check this very informative article from php.net http://php.net/manual/en/features.gc.php

Answer 5

Yes there is, [here]'s a nice article describing its pitfalls. In PHP > 5.3.0, there is also the gc_enable function.