PHP 出现问题“消息：count()：参数必须是数组或实现可计数的 object”

Question

Im completely new to PHP, please dont judge me by code it is not of my doing Im just fixing someone elses poor code. I got a task in job to fix issue with count() function.

Theres variable called $var which has a result function count() with variable in it.

the problem is that I get error on this line

$has = count($var); // Message: count(): Parameter must be an array or an object that implements Countable

Heres the snippet of the code:

if($l)
foreach($list[$key] as $k=>$v){
    $var = @$c->content->config['has'][$v['type']];
    $has = count($var);
    echo '<li class="',($k==$l-1?'last ':''),($has?'folder ':'file ' ),(isset($list[$v['url']])?'open ':''),'type_',($v['type']),'"><span onClick="tree_tog(this)"></span><a href="',site_url('panel/'.($has?'index':'edit').'/'.$v['lang'].'/'.$v['nid'],null,false),'">',character_limiter($v['name'],40),'</a>';
    if($v['type']!='root'&&isset($list[$v['url']]))
        pr($list,$v['url'],$c);
    
    echo '</li>';
}

How can I fix this error? Anyone? please!!

Answer 1

See the documentation for the count() function.

In your code, you have,

$has = count($var);

This means you are trying to count the elements of $var or more specifically, the object or literal that the $var variable refers to. Now, the count function can count elements of an array or any other object that is said to be countable . Not everything is countable. For instance, if you have an integer variable $price = 200; then the variable does not contain any elements in it, rather it has a number. So, the count function cannot count (the elements of) $price variable. Although, you could measure the length of the variable but that would be different than counting.

Simply put, you can count elements of an array or an object that has its properties structured in a way so that they can be countable. Otherwise, count() will fail and show that warning.

Try printing out the variable and see if you can figure out what's in it. There are several ways to print/debug in PHP objects,

print_r($var);

Or,

var_dump($var);

Happy coding.