passing variables from HTML to php page

chartpaper

I am just starting to play with PHP and downloaded these two files off the internet and I can not make them work. This should be a HTML page that ask for a number and then calls a php. Depending on the number it could retun another response. What is wrong (my setup or the code)?

============= passvar.html ==========
<HTML>
<HEAD>
<TITLE>Pass Variables</TITLE>
</HEAD>
<BODY>

<FORM METHOD="POST" ACTION="passvar.php">
Enter a numeric value:
<BR><INPUT TYPE="TEXT" NAME="number">
</FORM>
</BODY>
</HTML>
============= passvar.php ==========
<HTML>
<HEAD>
<TITLE>Pass Variables</TITLE>
</HEAD>
<BODY>

<?php
echo "The number entered was: $number.";
if ($number > 10)
echo "<BR>That's a big number.";
?>
</BODY>
</HTML>

LordShryku

Most likely a [man]register_globals[/man] problem. Try changing this:

<?php
echo "The number entered was: $number.";
if ($number > 10)
echo "<BR>That's a big number.";
?>

# to this

<?php
if(isset($_POST['number'])) {
   echo "The number entered was: ".$_POST['number'];
   if ($_POST['number'] > 10)
      echo "<BR>That's a big number.";
}
else {
   echo "No number was passed";
}
?>

chartpaper

Good news, your method of passing variables worked. Bad news is that your "if" statement that used isset did not work.

Is this because the isset statement takes a carriage return as a variable?
In my debugging I made a echo statement that put a X before and after my number variable.

The way the html is written I have to hit enter in this field to go to the php page. I will look for a way to display the carriage return to see if my quess is correct.
I will take help 🙂

chartpaper

My theory was wrong. Can someone tell me, why the isset code that was posted does not work?

I added more varaibles and a submit button to make sure that nothing was ever placed into that field. The "if" statement that I was given does not work.

gufmn

Originally posted by chartpaper
My theory was wrong. Can someone tell me, why the isset code that was posted does not work?

I added more varaibles and a submit button to make sure that nothing was ever placed into that field. The "if" statement that I was given does not work.

Works fine here.

paulnaj

I seem to remember having similar problems and fixed it using !isset() to fix it, although I can't quite see why ...

<?php 
if(!isset($_POST['number'])) { 
   echo "No number was passed"; 
else { 
   echo "The number entered was: ".$_POST['number']; 
   if ($_POST['number'] > 10) 
      echo "<BR>That's a big number."; 
} 
} 
?>

As I say, I can't really see why this works (for me, at least) ... maybe someone can explain.

Paul.

chartpaper

Paul the "!" makes the logic negative in a statement, so you made the statement say that It is not set. Also to let you know your code does not work. You have misplace a } in your code. If you want to see when a "{" matches a "}" put you cursor on the either one and then hit "%" key.

Can someone take the html code I provided and make it work with the isset code (postive or negative in this thread? Or tell me why it does not work. Thanks

TheDefender

When you post the form, the variable will always be set... It's a matter of whether or not the variable has a value assigned to it... So, you need to check to see if it is empty or not and you may as well check to see if it is, in fact, a number as well.

<?php  

if(isset($_POST['number']) && $_POST['number'] != "" && is_numeric($_POST['number'])) {  

    echo "The number entered was: ".$_POST['number'];  

if($_POST['number'] > 10) { 
    echo "<br />That's a big number.";  
} 

} else { 
    echo "No number was passed";  

} 
?>

paulnaj

chartpaper, sorry about the typo's.

This works for me (every time)...

<?php  

if(!isset($_POST['number'])) {  

   echo "No number was passed";  

}  else {  

   echo "The number entered was: ".$_POST['number'];  

   if ($_POST['number'] > 10)  

      echo "<BR>That's a big number.";  

}  

?>

As 'TheDefender' says, isset($POST['var']) will always return 'true', but what confuses me is why, if that is so, !isset($POST['var']) can return 'true' (surely only 'false').

I could be wrong (of course).

Paul.

EDIT: hit the submit button too quickly

The_Chancer

One little exception to the posting the form will always make a variable set is checkboxes....

You will have to use !isset($_POST['checkbox']) to see if those are set - as if they are not checked - no variable is passed...

TheDefender

TheChancer, thanks for the followup. I guess I never really thought about checkboxes, since I make it a habit of always checking to see if the passed variable is set, and checking to see if it has a value...

paulnaj, if you are passing an input type to the script, then in theory, yours should always go to the else portion of your statement. You have basically just flipped the statement, and checked first for a false, whereas we are checking for a true... Either way, they should work just the same.

paulnaj

Hi TheDefender,

Yeah ... what you say makes complete sense, of course, and makes me feel that I must've been making some elementary 'logic' error.

I remember having awkward problems but I'd best check back and see what they actually were rather than speculating.

Cheers,
Paul.

chartpaper

ok, I may not be in this forum very long, because I am going to make some people very upset. Could someone take the code HTML code and call your php code or some php code and actually make it work. I understand your code, IT JUST DOES NOT WORK WHEN CALLED FROM THE HTML. If you can not do this then I need to know how to do something that will work. The code looks simple it just does not work. I even tried a submit button and that did not change anything. Please take this code both part and test before you give a answer that does not work. Or tell me what I am missing to make mine work. Everything else seems to work other than this code.
==== passvar.html ======
<HTML>
<HEAD>
<TITLE>Pass Var</TITLE>
</HEAD>
<BODY>

<FORM METHOD="POST" ACTION="g.php">
Enter a numberic value:
<BR><INPUT TYPE="TEXT" NAME="number">
<INPUT TYPE="SUBMIT" VALUE="Submit">
</FORM>
</BODY>
</HTML>
====== passvar.php =======
<HTML>
<HEAD>
<TITLE>Pass Var</TITLE>
</HEAD>
<BODY>

<?php
if(isset($POST['number']) && $POST['number'] != "" && is_numeric($POST['number'])) {
echo"The number entered was: ".$_POST['number'];

if($_POST['number'] > 10) {
    echo "<br />That's a big number.";
}

} else {
echo "No number was passed";
}
?>

</BODY>
</HTML>

gufmn

I have tested this and it works. A couple things I noticed about your code: "echo_" should just be "echo", also you say you have a file called passvar.php yet your form action is g.php?
Anyway, I know this works.

<HTML>
<HEAD>
<TITLE>Pass Var</TITLE>
</HEAD>
<BODY>
<!-- File g.php -->
<?php
if(isset($_POST['number']) && $_POST['number'] != "" &&
    is_numeric($_POST['number'])) {
    echo "The number entered was: ".$_POST['number'];

if($_POST['number'] > 10) {
    echo "<br />That's a big number.";
}

} else {
    echo "No number was passed";
}
?>

</BODY>
</HTML>

good luck.

stenk

Originally posted by chartpaper

==== passvar.html ======
<HTML>
<HEAD>
<TITLE>Pass Var</TITLE>
</HEAD>
<BODY>

<FORM METHOD="POST" ACTION="g.php">
Enter a numberic value:
<BR><INPUT TYPE="TEXT" NAME="number">
<INPUT TYPE="SUBMIT" VALUE="Submit">
</FORM>
</BODY>
</HTML>
====== passvar.php =======
<HTML>
<HEAD>
<TITLE>Pass Var</TITLE>
</HEAD>
<BODY>

<?php
if(isset($POST['number']) && $POST['number'] != "" && is_numeric($POST['number'])) {
echo"The number entered was: ".$_POST['number'];
if($_POST['number'] > 10) {
    echo "<br />That's a big number.";
}
} else {
echo "No number was passed";
}
?>

</BODY>
</HTML> [/B]

Chartpaper this Script will not run looking at the naming convention used to name the HTML and PHP files

For a start it is looking for "g.php" not "passvar.php" as it states above.

If I change it to what it should be, it runs OK for me.

Also what errors do you get if any!
Try and give as much information as possible as to your problem.

chartpaper

thank goodnes for junior members - thanks gufmn and stenk. Thanks for actually looking at the code that was sent. Somewhere in the 2000 iterations of this simple code I left my file pointed at one of my other test piece of code. The other thing I learned is the isset does not work without other logic. I have to use isset a && !="" or && is_numeric
ALso thanks for pointing out the mistake of the echo_, I do not know how that got there since I cut and pasted the code. It is not anywhere in the real code I was using.
Thanks so much 🙂

gufmn

Glad to hear you got it working.

Don't forget to mark this thread resolved 🙂

paulnaj

chartpaper,

No need to get stroppy. Nobody is obliged to help you. I tried, and so did others but I certainly wasn't looking for a list of typo's in your script.

You were lucky to get someone to proof-read your code and identify your elementary errors. This is not the correct way to post questions. You are supposed to do this for yourself (look at the guidelines).

If you had debugged properly before posting, you would have found the errors as stenk and gufmn did.

Paul.

Don't forget to mark this thread resolved

TheDefender

Hey paulnaj, check out the response I got on his other thread in the double-post.

His other thread

Nothing like an ungrateful newbie.

gufmn

omgwtfbbq!

Defender: you are so 1337 right now!
Sadly, I know if you reply to this, you will be 1338 🙁