尝试在其中加载另一个数组时，PHP数组会引发错误

Question

I am finding the following error: "Warning: htmlspecialchars() expects parameter 1 to be string, array given..."

This happens in the following piece of code and only when I added input fields to the form whose name was an array (so I could repeat the input multiple times). The line the error refers to is ($v=htmlspecialchars($value);)

if ($len > 2) {
    $values=array();
    $possible=array('orderId','source','date', 'clientPrice','firstName','lastName','email','address','city','zip');
    $i=1;
    $query2 = "UPDATE orders SET ";
    foreach ($_POST as $key => $value) {
        $k=htmlspecialchars($key);
        $v=htmlspecialchars($value);
        if(in_array($k, $possible)) {
            $query2 .= $k." = ?";
            $values[]=$v;  //append values to an array for later use
            if($i < ($len-2)) $query2 .= ', ';
            $i++;
        }
    }
}

Any idea of how to solve this and the reason for the error?

Answer 1

You answered your own question in the first paragraph. You passed an array as values, therefore $value is going to be an array of the various inputs you assigned an array name to.

foreach($_POST as $key => $value)
{
    if ( ! is_array($value))
    {
        // Manage values that aren't arrays
    }
}

Iterating over $_POST isn't really a good practice. You would be better assigning the actual names of the fields to their own variables or creating your own array with the exact data you need.