Please explain the design (PHP)?

Question

PHP

Please explain what kind of check is performed in this construction:

if (!(isset($numer['image']))){
            $numer['image'] = '-1';
            $image_path = $html_sub->find('div.product_info div.image div img')[0]->src;
        }

Answer 1

Checks if $numer['image'] exists, and if it doesn't exist, sets it to "-1"

Answer 2

If $numer['image']undefined, the method searches for the specified string, before setting the value$numer['image'] = '-1';

Answer 3

Here is a link from the site tdme.ru/product/nizvolobor/380/#
Present in the table either Photo or Image. It turns out that if there is no tag with the name, then the code will not be executed. But it is being fulfilled.
$table_of_goods = $html_sub->find('div#modal_table table.mod_t')[0]->children;
$table_header = $table_of_goods[0]->find('tr')[0];
$table_body = $table_of_goods[1]->children;
$number = array();
// Pull out the cell numbers with the columns we need
foreach (($table_header->children) as $num => $th_row) {
// echo "FIRST foreach
";
//var_dump($th_row->plaintext);
//var_dump($num);
switch(trim($th_row->plaintext)){
case 'Name':
case 'Light name':
$numer["name"] = $num;
break;
case 'Photo':
case 'Image':
$numer['image'] = $num;
break;
case 'Article':
$numer['model'] = $num;
break;
}
}
if (!(isset($numer['image']))){
$numer['image'] = '-1';
}
//echo "";
$rowspan = 1;

Answer 4

What exactly is $numer['image'] in the problem case? php.net/manual/en/types.comparisons.php