Re: re-using variables

Ivan Marsh wrote:
On Tue, 27 Feb 2007 20:44:47 +0000, Tim Streater wrote:

In article <1172596225.876668.42750@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"Mitesh" <oopsbabies@xxxxxxxxxxx> wrote:

What I have discovered is re-using the $req variable is fine. While re-
using the $res produces undefined result (sometimes the second query
works fine and sometimes it doesn't. When I use different variables
like $res1 and $res2 the mysql queries always succeed. Is the initial
approach of re-using variable wrong if variables contain a
resource(reference type)?

In other words since PHP uses garbage collection re-using the same
variable can cause problems. Is this true?
Pass. But I systematically do mysql_free_result($res) whether I need to
or not, not just before a re-use of $res in another query, but also at
the end of the script. I don't know how it works internally or how much
one needs to worry about this.

The resource gets freed automatically at the end of the script. It's
always a good idea to free something you're going to re-use in case your
code isn't working properly you could be left with old data still in the
resource that's hiding where your real issue is.



One correction. It gets freed when the garbage collector runs. This is sometime after the script ends, but may not be immediately.

I always free my results, close connections, and generally clean up for myself. It's just good programming practice.

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