Question

How can I check if each value in the variable $c = 90,89,78,88; equal true I think you call it an array in my script one at a time?

This part checks the variable.

if($cat['id'] == $c){
    $url = $parent_url . $cat['url'];
    echo '<a href="' . $url . '" title="' . $cat['category'] . '">' . $cat['category'] . '</a>';            
}

Here is the PHP code.

$c = 90,89,78,88;

function make_list ($parent = 0, $parent_url = '') {
    global $link;
    global $c;

    foreach ($parent as $id => $cat) {

        if($cat['id'] == $c){
            $url = $parent_url . $cat['url'];
            echo '<a href="' . $url . '" title="' . $cat['category'] . '">' . $cat['category'] . '</a>';            
        }

        $url = $parent_url . $cat['url'];

        if (isset($link[$id])) {
            make_list($link[$id], $url); // $url adds url value to sub categories
        }               
    }       
}

Answer 1

global $c; 

$cArray = explode(',',$c);

foreach ($parent as $id => $cat) { 

    if (in_array($cat['id'],$cArray)) {