How to replace a nth occurrence in a string

Question

I need a simple and fast solution to replace nth occurrence (placeholder) in a string.

For example, nth question mark in sql query should be replaced with a provide

Answer 1

None of your solutions worked for me, so I made this:

$sql1 = "SELECT * FROM allegro_user WHERE User_Emp_Nb = ? AND User_Activ_status = ?";
$sql2 = "SELECT * FROM allegro_user WHERE User_Emp_Nb = :emp_nb AND User_Activ_status = :activ";

function prepare_query($sql, $args) {
    foreach ($args as $key => $value) {
        if (is_numeric($key)) {
            $sql = preg_replace('/\?/', "'" . $value . "'", $sql, 1);
        } else {
            $sql = str_replace($key, "'" . $value . "'", $sql);
        }
    }
    return $sql;

}

tab($sql1);
$sql = prepare_query($sql1, array('0216313', 'A'));
tab($sql1);

tab($sql2);
$sql = prepare_query($sql2, array(':emp_nb' => '0216313', ':activ' => 'A'));
tab($sql2);

tab() is just a function I use for printing :

echo '
';
print_r($tab);
echo '
';