Codeigniter 2 with variable reference error in PHP version 5.6

Question

Codeigniter 2 with variable reference error in PHP version 5.6

I am 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

In line 257 has a strange code:

return $_config[0] =& $config;

This message started to appear since I updated the version from PHP to 5.6.

Why does this error occur? How can I solve it?

1

php codeigniter codeigniter-2

Author: Wallace Maxters, 2017-01-16

Source

1 answers

score 5 · Accepted Answer

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 method signature get_config(), which forces the return to be a reference (variable).

If you can measure the impact of the change, another solution is to remove & from the signature. How this snippet of code is part (Comum/ Common ;) ) of the framework, it may result in unexpected.

Signature:

function &get_config($replace = array())

Change:

return $_config[0] =& $config;

To: as fixed in 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 on various php versions.