if not expression

[p3aul]

Hi!

i am wanting to veryify data from a form textfield. All I want is digits like this 99.9 with a minus sign optional OK so I can use regular expressions and preg_match() for this.

 

My problem is I want to use an if expression and popup an alert box if the match is not successful(ie there is something other than a number , (-) sign or a period) here is what i have:

 

preg_match('/^\d+$/', $db)

if ( !=  preg_match('/^\d+$/', $db));{

echo '<script language="javascript">confirm("Must be numbers only!")</script>;'; }

 

but this just causes an error page with this:

Parse error: syntax error, unexpected T_IF in C:\xampp\htdocs\Untitled-2.php on line 71

 

This almost as clear as mud!

Any help would be gratefully appreciated!

Paul

 

 

 

[trq]

if (!preg_match('/^\d+$/', $db)) {

[p3aul]

OK I saw my mistake about the Exclamation point! apparently PHP doesn't use this as a symbol for *not* in and if statement. I corrected it to:

 

if (preg_match('/^\d+$/', $db)== false);{

echo '<script language="javascript">confirm("Must be numbers only!")</script>;'; }

 

and added an "else" statement but it still doesn't work! In the interest of keeping the post short I have uploaded the relevant code. Bear in mind that I only verify one variable($db) for testing purposees. If I can get this worked out the rest should follow. My math maybe convoluted, but I know it works!

 

[attachment deleted by admin]

[DarkWater]

PHP does indeed use ! as its NOT symbol.  The reason for the first error was due to the fact that you didn't terminate the (very random) preg_match() on the line above the IF with a semicolon.

[p3aul]

Ok, I finally got it to work with ! used in the if expression. But now I can address another issue.

 

When the page loads, somehow the code falls through to the javascript alert box first. I click ok and the code functions normally. This happens with what ever I put as the initial value of db in the textfield. I've tried it with blanks, zeros, and 111. It still falls through. Here is the little bit of code where I have my problem

 

$db = $_POST["db"];
$wb = $_POST["wb"];
$pr = $_POST["pr"];
//
// For testing purposes only I'm only verifying $db
//

if ( ! preg_match('/^\d+$/', $db)){
echo '<script language="javascript">confirm("Must be numbers only!")</script>;'; } 
// Calculate Ew, the wetbulb vapor pressure component
else {
$F = 6.112 * exp((17.67*$wb)/($wb+243.5));

[CroNiX]

extra semicolon

echo '<script language="javascript">confirm("Must be numbers only!")</script>;'; }

[p3aul]

extra semicolon

echo '<script language="javascript">confirm("Must be numbers only!")</script>;'; }

 

Well that was the bit of code I copied from a forum asking how to use an alert box in PHP. On the face of it it makes sense, php is echoing javascript code and that code requires a semicolon also. then the PHP code needs a semicolon to complete it. In any case the point is moot. The javascript still slips through on load with or without the semicolon and I get no error in either case.

 

I'm still looking