PHP Error: invalid argument supplied for foreach() - php

Question

I'm trying to use this function at the bottom of a plugin's main PHP file to determine if one of its action hooks is being used by the tag specified. However, I'm getting a "Warning" on the 2nd foreach in the code below. Why is this? Is there a better way to see if a Wordpress action hook is being used?
<?php
function dump_hook($tag, $hook)
{
ksort($hook);
echo "<pre>>>>>>\t$tag<br>";
foreach ($hook as $priority => $functions) {
echo $priority;
foreach ($functions as $function) {
if ($function['function'] != 'list_hook_details') {
echo "\t";
if (is_string($function['function']))
echo $function['function'];
elseif (is_string($function['function'][0]))
echo $function['function'][0] . ' -> ' . $function['function'][1];
elseif (is_object($function['function'][0]))
echo "(object) " . get_class($function['function'][0]) . ' -> ' . $function['function'][1];
else
print_r($function);
echo ' (' . $function['accepted_args'] . ') <br>';
}
}
}
echo '</pre>';
}
$tag = array('anspress_loaded');
$hook = array('find_do_for_anspress');
dump_hook($tag, $hook);

Answer 1

Some errors from your code:
1.) $tag is array, but in your function it's used as string:
<?php
echo "<pre>>>>>>\t$tag<br>";
2.)$hook is array, so first foreach works ok:
<?php
// for first row
// $priority is int 0
// $functions is string find_do_for_anspress
foreach($hook as $priority => $functions ) {}
Next you try to do foreach with string $functions, but it's not iterrable, so php says to you aforementioned error.