MySQLi equivalent of mysql_result()?

The following function fully replicates the mysql_result() function, and returns false when you are out-of-bounds on your request (empty result, no row of that number, no column of that number). It does have the added benefit that, if you don't specify the row, it assumes 0,0 (one less value to be passed). The function allows for the numerical offset of the field or the field name.

function mysqli_result($res,$row=0,$col=0){ 
    $numrows = mysqli_num_rows($res); 
    if ($numrows && $row <= ($numrows-1) && $row >=0){
        mysqli_data_seek($res,$row);
        $resrow = (is_numeric($col)) ? mysqli_fetch_row($res) : mysqli_fetch_assoc($res);
        if (isset($resrow[$col])){
            return $resrow[$col];
        }
    }
    return false;
}

PHP 5.4 now supports function array dereferencing and 7.0 supports a null coalescing operator, which means you can simply do this:

$value = $r->fetch_assoc()['blah'] ?? false;  

or even more generic variant where you don't need to supply the column name,

$value = $r->fetch_row()[0] ?? false;  

note that you don't even need the if ($r && $r->num_rows) condition.