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Hi there, I have a simple question to ask: Say i have a PHP script: <?php var_dump($undeclaredVariable); /* The output is NULL */ if($a==$b) { if($c == $d) { $undeclaredVariable = TRUE; } else { $undeclaredVariable = FALSE; } } if($undeclaredVariable == TRUE) { echo 'the undeclared variable is TRUE'; } if($undeclaredVariable == FALSE) { echo 'the undeclared variable is FALSE'; } ?> Reading the PHP Type Comparison Table: $x = null; boolean if($x) = FALSE Using the code above, I see the "the undeclared variable is FALSE", which is OK since it proves the PHP documentation. But as you can see, if $a !=$b then the $undeclaredVarable will not be declared(defined). Is this an "OK" way to work this out? Or should I find a way to declare the variable whatever the case? Thanks in advance, Christos

I'm trying to make a function that checks if there are enough seats available for visitors. If there's enough room for the visitors, return an array with suggested seats, else return null. Method: I'm making a gap, this gap will be increased by 1 everytime there is a available seat. At the end of my function, I compare if the $visitors fit in the $gap, if they don't return null and if they do, return the array. The problem: My function returns an array even though there's not enough room. My question: How do I let my function return null if there are not enough seats? This is my code: <?php error_reporting(E_ALL & ~E_NOTICE); $visitors = 6; $seats = array( array( 'seatAvailable' => '0', 'seatNumber' => '1' ), array( 'seatAvailable' => '0', 'seatNumber' => '2' ), array( 'seatAvailable' => '1', 'seatNumber' => '3' ), array( 'seatAvailable' => '1', 'seatNumber' => '4' ), array( 'seatAvailable' => '1', 'seatNumber' => '5' ), ); $gap = 0; echo "Visitors: ".$visitors; echo "<ol>"; function suggestSeats($seats,$visitors){ foreach($seats as &$val){ //If available if($val['seatAvailable'] == '1'){ //If there's no gap, start making one now: if($gap<1){ $gap = 1; } $gap++; //IF THERE ARE STILL VISITORS TO PROCESS, MARK THE SUGGESTED SEAT if($visitors > 0) { $val['seatAvailable'] = 'x'; $visitors--; } } //IF THERE ARE NO MORE VISITORS, EXIT LOOP if($visitors == 0) { break; } } //echo "gap".$gap; //If the visitors don't fit in the gap of available seats. if($visitors>$gap){ $result = null; } else{ $result = $seats; } return $result; } echo "</ol>"; echo "<pre>"; print_r (suggestSeats($seats,$visitors)); echo "</pre>"; ?> This is the output of my script as it is now: Visitors: 6 Array ( [0] => Array ( [seatAvailable] => 0 [seatNumber] => 1 ) [1] => Array ( [seatAvailable] => 0 [seatNumber] => 2 ) [2] => Array ( [seatAvailable] => x [seatNumber] => 3 ) [3] => Array ( [seatAvailable] => x [seatNumber] => 4 ) [4] => Array ( [seatAvailable] => x [seatNumber] => 5 ) ) I want it to show null instead of returning the array.

Hi guys, I've a little problem i have a fileld in my database that i want to check. If is null to display some text else display another text. I've manage to do something like this but doesn't work. The code is below: <?php $result = @$mysqli->query("SELECT * FROM depanarecuora_clients WHERE paid_status = '$paid_status'"); while ($result = mysqli_fetch_assoc($result)) if (is_null($paid_status)) { echo "some text"; } ?>

I have created a form to edit fields in a database table. This is basically what it does sale_stamp : <input type="text" name="sale_stamp" value="<?php echo $sale_stamp;?>" > $sale_stamp = $_POST['sale_stamp']; $sql = "UPDATE mytable SET sale_stamp = :sale_stamp WHERE id = :id"; $stmt=$db->prepare($sql); $stmt->execute(array( ':id' => $id, ':sale_stamp' => $sale_stamp); This works provided there are values entered but some fields may be blank and this fails for numeric fields. The generated sql is UPDATE asset set sale_stamp = '' WHERE id = '17' The table definition allows null, but when I leave the field blank in the table the generated sql has an empty string rather than null. How do I overcome this?