Bug #63156 [Opn->Dup]: using if ( expression ) requires functions to be declared before calls
Edit report at https://bugs.php.net/bug.php?id=63156&edit=1
ID: 63156
Updated by: laruence@php.net
Reported by: herb at bobbingwide dot com
Summary: using if ( expression ) requires functions to be
declared before calls
-Status: Open
+Status: Duplicate
Type: Bug
Package: *Programming Data Structures
Operating System: Windows XP
PHP Version: 5.3.17
Block user comment: N
Private report: N
New Comment:
dup to #17055
Previous Comments:
------------------------------------------------------------------------
[2012-09-25 05:13:48] reeze@php.net
Top level declaration are available after compiling, but conditional declaration
can only be available after executed. (since PHP itself didn't do optimization,
if(true) {doSomething();} is not equal to doSomething(); exactly )
the same rules for class declarations.
This could be classified as a documentation problem.
------------------------------------------------------------------------
[2012-09-25 02:40:07] laruence@php.net
it is good manner always declare function/class before using it.
------------------------------------------------------------------------
[2012-09-24 19:56:55] herb at bobbingwide dot com
Description:
------------
When enclosing code between if ( expression ) { and } it appears that versions
of PHP up to and including 5.3.17 require functions to be declared before they
are used. I first noticed the problem when I tried to wrap a whole PHP source
file like this
<?php
if ( !defined( 'CONSTANT' )) {
define( 'CONSTANT', true );
// whole file here
} // end defined
I reduced the problem to the simplest; replacing !defined( 'CONSTANT') with true
and got the same unexpected results. The code did not work unless the (top
level) functions were declared before they were used.
I found the problem on PHP 5.3.5 where the code produced a Fatal error: Call to
undefined function. I have since reproduced the Fatal error on PHP 5.3.16 and
5.3.17
If you remove the 'if test' (lines 2 and 7) the code works fine.
If you put the call to the function after the declaration that also works.
This code, where the call to b() is before the declaration of function b, also
works
<?php
if ( true ) {
function a() {
echo "a" . PHP_EOL;
b();
}
function b() {
echo "b" . PHP_EOL;
}
a();
}
producing
a
b
Test script:
---------------
<?php
if ( true ) {
a();
function a() {
echo "a" . PHP_EOL;
}
}
Expected result:
----------------
a
Actual result:
--------------
Fatal error: Call to undefined function a() in C:\apache\htdocs\wordpress\wp-con
tent\plugins\play\defined.php on line 3
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=63156&edit=1
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