"Fatal error: Cannot redeclare <function>"

user_224225 0
Viewed 169496

I have a function(this is exactly how it appears, from the top of my file):

<?php
//dirname(getcwd());
function generate_salt()
{
    $salt = '';

    for($i = 0; $i < 19; $i++)
    {
        $salt .= chr(rand(35, 126));
    }

    return $salt;
}
...

And for some reason, I keep getting the error:

Fatal error: Cannot redeclare generate_salt() (previously declared in /Applications/MAMP/htdocs/question-air/includes/functions.php:5) in /Applications/MAMP/htdocs/question-air/includes/functions.php on line 13

I cannot figure out why or how such an error could occur. Any ideas?

include php
18 Answers

This errors says your function is already defined ; which can mean :

  • you have the same function defined in two files
  • or you have the same function defined in two places in the same file
  • or the file in which your function is defined is included two times (so, it seems the function is defined two times)

To help with the third point, a solution would be to use include_once instead of include when including your functions.php file -- so it cannot be included more than once.

user_1384750

You're probably including the file functions.php more than once.

user_2276650

I don't like function_exists('fun_name') because it relies on the function name being turned into a string, plus, you have to name it twice. Could easily break with refactoring.

Declare your function as a lambda expression (I haven't seen this solution mentioned):

$generate_salt = function()
{
    ...
};

And use thusly:

$salt = $generate_salt();

Then, at re-execution of said PHP code, the function simply overwrites the previous declaration.

user_9308790

I'd recommend using get_included_files - as Pascal says you're either looking at the wrong file somehow or this function is already defined in a file that's been included.

require_once is also useful if the file you're attempting to include is essential.

user_1098250

I would like to add my 2 cent experience that might be helpful for many of you.

If you declare a function inside a loop (for, foreach, while), you will face this error message.

user_13243660

Since the code you've provided does not explicitly include anything, either it is being incldued twice, or (if the script is the entry point for the code) there must be a auto-prepend set up in the webserver config / php.ini or alternatively you've got a really obscure extension loaded which defines the function.

user_2239920

If your having a Wordpress theme problem it could be because although you have renamed the theme in your wp_options table you havn't renamed the stylesheet. I struggled with this.

user_16950620

I had this pop up recently where a function was being called prior to its definition in the same file, and it didnt have the returned value assigned to a variable. Adding a var for the return value to be assigned to made the error go away.

user_1772420

You have to deactivate the lite version in order to run the PRO version.

user_167465040
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