[SOLVED] how do I ensure that numbers are entered into a variable?

[kr3m3r]

Hi guys, thanks for reading this and any help you can give me.  I'm new to programming so I appologize if this is a goofy question.

I have a page where a customer can input the quanitiy of items they wish to buy of four different things: tires, spark plugs, oil, and engine blocks.  I'm trying to ensure that the visitors only put integers into the text boxes but i keep getting errors.  Here is my php code that is problematic:

 

 

  $tiretype=gettype($HTTP_POST_VARS['tireqty']);

  $oiltype=gettype($HTTP_POST_VARS['oilqty']);

  $sparktype=gettype($HTTP_POST_VARS['sparkqty']);

  $enginetype=gettype($HTTP_POST_VARS['engineqty']);

 

  if(is_int(tiretype)==false || is_int(oiltype'])==false ||

    is_int(sparktype'])==false || is_int(enginetype'])==false)

  {

  echo '<p>';

  echo '<font color=red>';

  echo '<h1>';

  echo 'You did not enter numbers!';

  echo '</h1>';

  echo '</font>';

  echo '</p>';

  }

 

Thanks again for the help,

-Robb

[pocobueno1388]

Use is_numeric() instead of is_int()

 

if(!is_numeric($tiretype) || !is_numeric($oiltype) || !is_numeric($sparktype) || !is_numeric($enginetype))

[kr3m3r]

I tried posting that and now it says all input is not a number.  If it helps the relavent html code is:

td align="center"><input type="text" name="sparkqty" size="3" maxlength="3">

Thanks

-Robb

[lur]

gettype() returns a string, thus:

$variable = gettype($something);
is_int($variable); // always FALSE;

 

$tiretype = $HTTP_POST_VARS['tireqty'];

if (FALSE === is_numeric($tiretype)) {
// it's not numeric.
}

[pocobueno1388]

Change this:

  $tiretype=gettype($HTTP_POST_VARS['tireqty']);
  $oiltype=gettype($HTTP_POST_VARS['oilqty']);
  $sparktype=gettype($HTTP_POST_VARS['sparkqty']);
  $enginetype=gettype($HTTP_POST_VARS['engineqty']);

 

To:

 

  $tiretype = $_POST['tireqty'];
  $oiltype = $_POST['oilqty'];
  $sparktype = $_POST['sparkqty'];
  $enginetype = $_POST['engineqty'];

[xyn]

preg_match();

[GingerRobot]

Using regular expressions to check for numeric data is a bit unnecessary. There are quicker methods.

[kr3m3r]

If I may ask, what are the quicker methods? I've just started working my way through my PHP book, and I've been trying to use what has been brought up so far.  The book suggested as a challenge to myself I try to implement some sort of error protection.  So I'd love to know more.  Thanks to everyone for replying so far, I really appreciate it.

-Robb

ps what does "preg_match();" refer to?

Thanks again!

[drewbee]

Please note that is_numeric allows floating numbers to be entered as well.

[pocobueno1388]

Give this a try:

 

<?php

if (!is_numeric($tiretype) || strstr($tiretype, '.')){
    echo "Bad Input!";
} else {
    echo "Good Input!";
}

?>