How to exclude an item in an array in PHP

Use unset() to remove an item in a array. But you have to provide a key and the value to the array.

$p["p1"]="abc";
$p["p2"]="efg";

then,

unset($p["p1"]);

Try in_array() or array_key_exists();

$products= [1,2,3,4,5]; 
$array=[1,5];
foreach($products as $key => $product){
    if (array_key_exists($key,$array)){
        unset($products[$key]);
    }
}

this should do the trick, // loop through the new array to create your html

$html = '';
foreach($products as $key => $product){
   $html .= '<a href="'.$product['id'].'">$product['name']  </a>';
}
echo $html;

$array = array("a","b","c","d","e");
$array2 = array("d","b");
shuffle($array);
for($i=0;$i<count($array2);$i++) {
    if(stristr($array[0],$array2[$i])) {
        unset($array[0]);
    }
}

echo $array[0];

You should have the current product stored somewhere, so you just need to compare that value with the values in your $products array. You can use in_array to find the $current_product in the $products array. Something like the below:

$current_product = '1';
$products = array('1', '2', '3', '4');

if (in_array($current_product, $products)) {
  unset($products['key'])
}

You can use unset() to remove the value from the array, but be sure to supply the array key or index value when you do so.

UPDATE:

After a conversation with the OP:

I think you need to restructure your code. If you can restructure the HTML in products.php, then store all of your products, including the main product, in php variables. Then, print out the main product and additional products to the page with php variables. Something like:

<!-- Main Product Code -->
<?php print $main_product ?>

<!-- Customers Also Bought -->
<?php print $products[0] ?>

That way all of your data is stored in PHP variables. If it is all stored in variables then you can use PHP to compare the two products with the method above.

HOWEVER, if you can't change products.php then you are going to need to parse through the HTML and find some identifying information that will indicate which product is being shown. After you identify the product, you will then need to compare it with the HTML which you stored in $products to find a match. Basically, you need to compare one string against another, and you really don't want to have to go down that route.

Ok, after reading and trying to implement all of the offered suggestions without success I came up with a solution that will work for me. I realize that this is a more crude way of doing it but it is the only way I could achieve what I needed.

I modified the php file that contained all of the product names and html to be echoed on the main product pages.

$all_products = array($product1, $product2, $product3, $product4, $product5); // for all non-promoted products pages
$for_product5 = array($product1, $product2, $product3, $product4); // for Product 5 page
$for_product4 = array($product1, $product2, $product3, $product5); // for Product 4 page
$for_product3 = array($product1, $product2, $product4, $product5); // for Product 3 page
$for_product2 = array($product1, $product3, $product4, $product5); // for Product 2 page
$for_product1 = array($product2, $product3, $product4, $product5); // for Product 1 page

shuffle($all_products);
shuffle($for_product1);
shuffle($for_product2);
shuffle($for_product3);
shuffle($for_product4);
shuffle($for_product5);

This way I can echo on each page only the items I want to be randomly shown on that page.

Yes, I know that there is probably a much better way of doing it but this gets me going for now.

Thanks for all of the help though.