In case you need to print out hidden input fields from an array, such as from $_GET

hidden_input_from_array.php

<?php
/**
 * @param array|string $input the input array. also works as the value when you have a name and a value only, not array
 * @param string|null $name_prefix the name of the input field. You pass it when you have just a name and a value, not array
 * @return void
 */
function generateHiddenInputFromArray(array|string $input, ?string $name_prefix = null): void {
    if(is_array($input)){
        foreach($input as $i=>$v){
            $name = !is_null($name_prefix) ? $name_prefix.'['.$i.']' : $i;

            if(is_array($v)) generateHiddenInputFromArray($v, $name);
            else echo '<input type="hidden" name="'.$name.'" value="'.$v.'">';
        }
    }
    else echo '<input type="hidden" name="'.$name_prefix.'" value="'.$input.'">';
}