PHP array_walk require_once

Question

I was just wondering if anyone knew why I can't use require_once as a callback for array_walk. I can just include it in an anonymous function and run that, but it gives an invalid callback error for the usage:

$includes = array(
    'file1.php',
    'file2.php',
    'file3.php'
);
array_walk($includes, 'require_once');

require_once isn't a function, it's a language construct, so it can't be called directly as a callback function — Mark Baker
– Mark Baker, Commented Jan 7, 2014 at 16:50
...it would also error with an invalid callback if you tried to use array_walk($includes, 'echo') as echo is a language construct not a function. — Michael Berkowski
– Michael Berkowski, Commented Jan 7, 2014 at 16:51
+1 to both previous comments. But seriously, any good reason why you aren't just using a foreach() loop here? — Spudley
– Spudley, Commented Jan 7, 2014 at 16:53
Thanks guys, just did a foreach loop like zigi said, but it perturbed me that I couldn't do it on a single line and keep my code extra clean. — Peter
– Peter, Commented Jan 7, 2014 at 18:23

Martin · Accepted Answer · 2014-01-07 16:50:51Z

6

require_once is not a PHP function, but a control structure.

answered Jan 7, 2014 at 16:50

Martin

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Comments

kanlukasz · Accepted Answer · 2021-12-21 14:16:37Z

3

You are going to waste more time finding out what's wrong. Just use:

$includes = [
    'file1.php',
    'file2.php',
    'file3.php'
];
foreach($includes as $include) {
    require_once($include);
}

edited Dec 21, 2021 at 14:16

kanlukasz

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answered Jan 7, 2014 at 16:52

ziGi

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Comments

spraff · Accepted Answer · 2014-01-07 16:51:23Z

2

You could create

function my_require_once ($name)
{
    require_once $name;
}

The other guys are right, it's not a function. It operates outside the mode of the PHP code you write. The contents of the file are brought into the global namespace, even if it is called within a functiion, as above.

I use this, for example to do stuff like

function my_log ($message, $extra_data = null)
{
    global $php_library;
    require_once "$php_library/log.php"; // big and complicated functions, so defer loading

    my_log_fancy_stuff ($message, $extra_data);
}

answered Jan 7, 2014 at 16:51

spraff

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Comments

Dmitriy.Net · Accepted Answer · 2014-01-07 17:30:18Z

0

As Martin wrote, require once is not a function, so your solution with array_walk is not been working. If you want to include multiple files, you can try to use this:

function require_multi($files) 
{
    $files = func_get_args();
    foreach($files as $file)
    {
        require_once($file);
    }
}

Usage:

require_multi("fil1.php", "file2.php", "file3.php");

answered Jan 7, 2014 at 17:30

Dmitriy.Net

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