I'm using Codeigniter version 2.1.3 and when I open any page the following error is displayed:
A PHP Error was encountered
Severity: Notice
Message: Only variable references should be returned by reference
Filename: core / Common.php
Line Number: 257
At line 257 has a strange code:
return $_config[0] =& $config;
This message began to appear since I updated the PHP version to 5.6.
Why does this error occur? How can I resolve it?
The Codeigniter framework has a great legacy, so it uses some techniques that have fallen into disuse. The problem in this case is the & in the signature of the get_config() method, which forces the return to be a reference (variable).
If you can measure the impact of the change, another solution is to remove the & of the signature. Since this code snippet is part of ( Comum / Common ;)) of the framework, it can lead to unexpected behavior.
Signature:
function &get_config($replace = array())
Change:
return $_config[0] =& $config;
To: as corrected in the version 2.2.x
$_config[0] =& $config;
return $_config[0];
A simple way to reproduce the error is with the following code:
function &olaMundo(){
return 'Ola mundo';
}
echo olaMundo(); //Notice: Only variable references should be returned by reference in
Correction:
function &olaMundo(){
$x = 'Ola mundo';
return $x;
}
Functional example run in various php versions.