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Is destructor in PHP predictable?

Posted by: admin July 12, 2020 Leave a comment

Questions:

Is a class destructor in PHP predictable? When is the destructor called?

Like in many languages, will a class destructor be called as soon as the object goes out of scope?

How to&Answers:

PHP 5 introduces a destructor concept
similar to that of other
object-oriented languages, such as
C++. The destructor method will be
called as soon as all references to a
particular object are removed or when
the object is explicitly destroyed or
in any order in shutdown sequence.

http://php.net/manual/en/language.oop5.decon.php

Answer:

It’s called when the first of these conditions are met:

  • The reference count of the object goes to 0 (these usually happens when the object has no more variables that reference it — they were unset or went out of scope –, but it can happen later, as an object may be referenced by something other than a variable — in fact, the reference count is just a number and can be manipulated in an arbitrary way).
  • When using PHP 5.3, when the garbage collector detects the positive reference count is due to circular references.
  • Otherwise, when the script finishes cleanly.

In short, you should not rely on it always being called, because the script may not finish cleanly.