PHP $_POST vs saving data in an array

Question

This is not an bug or issue. But while I was reading about a lot of performance realated articles I came to know about how javascript variables take more resources to load and so it is better to put the global variable for javascript into a local variable to work - specially in for loops.

So I was wondering if such thing also happens on $_POST with PHP. As in will it give me a performance improvement if I have lot of post data. Save that in a local array say $post_data = $_POST;

And then I reference in where required.

I don't think there will be an appreciable performance improvement, if any. — Ja͢ck, May 03 '13 at 07:25

Ben · Answer 1 · 2013-05-03T07:37:02.807

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Not really worth the time. $_POST is already an array in memory, so no need to duplicate it.

To get the size of $_POST in bytes, you can do this:

strlen(serialize($_POST));

(serialize will turn any object into a string which can be saved and unserialized. )

FWIW in for loops, if you don't cache the length of the array and instead use something like this...

for(var i = 0; i < myarray.length; i++) {}

...JS will have to recalculate .length each time it starts an iteration, so it's expensive, particularly over big arrays.

edited May 03 '13 at 07:37

answered May 03 '13 at 07:23

Ben

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The second part of your answer seems unrelated to the question. – Ja͢ck May 03 '13 at 07:26
@Jack - yeah just threw in my two cents...OP mentioned JS for loops, got excited :) – Ben May 03 '13 at 07:36

score 0 · Answer 2 · answered May 03 '13 at 07:26

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In php the main concern with globals is memory. Performance difference in accessing a global or local scoped variable is negligable.

answered May 03 '13 at 07:26

nvanesch

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score 0 · Answer 3 · answered May 03 '13 at 07:33

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Not sure about the JavaScript part (can you provide a reference, please?). In PHP this would effectively create a copy of $_POST array and hence would use more memory without having any effect on speed improvement.

answered May 03 '13 at 07:33

naivists

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score 0 · Answer 4 · answered May 03 '13 at 07:40

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If you make:

$post_data = $_POST;

PHP will create just reference to info in $_POST variable, so you will not have more memory usage, till changind info in $post_data. If you try to change data when PHP will create copy of information in memory.

answered May 03 '13 at 07:40

Narek

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PHP $_POST vs saving data in an array

4 Answers4