Stepping?

theDog

(gohere.php)

IF ($action == "next")
{
$id = $id++;
}
PRINT $id

If my URL says http://site.com/gohere.php?action=next&id=2 , shouldn't the page print "3"?
😕

Rodders

Not necessarily.

Go to www.php.net and lookup $POST and $GET and register_globals.

There you will find the answers.

rIkLuNd

<?php

$id = $_GET['id'];
$id++;

echo "<a href=\"gohere.php?id=".$id."\">Next</a>\n";

?>

cgraz

Try

<?

if ($action == "next") {
   $id = $id + 1;
}

print $id;

?>

Cgraz

dalecosp

Originally posted by theDog
B
IF ($action == "next")
{
$id = $id++;
}
PRINT $id
If my URL says http://site.com/gohere.php?action=next&id=2 , shouldn't the page print "3"?
😕 [/B]

What does the page print instead? Rodders and RikLunD are with it on this, if the var is in your URL, you still can't access it (with reg globals OFF) unless you call it from the superglobal array.

$id=$_GET['id'];      # this is necessary to 'receive' the var from URL
IF ($action == "next")
{
$id = $id++;
}
PRINT $id

Rodders

Don't forget.....

if ($_GET['action' == 'next')

theDog

It printed "2" or whatever $id i passed in the URL.

What cgraz said works fine, which really confuses me since i was cribbing from another script that works fine on the interweb, and i though ++ was equivalent to +1.

My local machine has register_globals on. Not sure what that means, and i will dutifully go php.net and try to figure it out. At this point i really need people who speak in English. I'm only here because i've Read so many of The F Manuals my eyes are crossed.

Er... my connection is funky today and so going to php.net doesn't seem to be an option ATM. Should i just always use the $_GET to be safe? In this case, i should use it for the $action variable too?

Thanks.
EDIT: Oh. Oops. What Rodders said...

dalecosp

Maybe we should see what it thinks the value of $action is?

echo "$action";
IF ($action == "next")
{
$id = $id++;
}
PRINT "$id";

What "register globals" means practically is this:

form 1 input says $var=1

RG ON: form 2 receives $var with value equal to 1.
RG OFF: form 2 must access the superglobal array to determine if $var is even extant; if the method was POST, for example, then $_POST['var'] will be equal to 1.

Note that this is true on later versions; before 4.1.0, I think, the array was $HTTP_POST_VARS[].

HTH,

Rohan_Hill

I think the only problem was that you were going $id = $id++; instead of just $id++;

dalecosp

Originally posted by Rohan Hill
I think the only problem was that you were going $id = $id++; instead of just $id++;

Jeepers!! And we all sat here on our bums staring....

theDog

That's the sort of thing that's killing me. Ya know, at some point i think i did just say $id++ but i probably had something else wrong. So then, $id++ means $id = $id + 1 (y/n?)

It's working, but just to clarify... i should ALWAYS use the $_GET? (y/n?). IOW, it will do no harm if register_globals is on?

Thanks again.

dalecosp

Originally posted by theDog
That's the sort of thing that's killing me. Ya know, at some point i think i did just say $id++ but i probably had something else wrong. So then, $id++ means $id = $id + 1 (y/n?)

It's working, but just to clarify... i should ALWAYS use the $_GET? (y/n?). IOW, it will do no harm if register_globals is on?

Thanks again.

It would work either way, but it's recommended to begin doing this, for compatibility with future versions, which will all have RG OFF as default, and sooner or later maybe not even have the option <who knows?>; also, Google a little on 'variable poisoning' and see why....

theDog

i posted elsewhere and they were cross with me... 🙁

This whole script i'm working on was counting on the auto incremented ID field. So if someone coming from URL #2, they go to URL #3.

The problem comes when i delete a record. If it counts 1,2,3,5,9, etc because records have been deleted, then there is no URL #6 for URL #5 to go to. It needs instead to go to URL #9.

I thought there ought to be a way to reindex a database when records are deleted. I was told, very succinctly, to use the count() function. I've thought and thought, and can't think how to accomplish what i said up ^there using the count() function. So i came back to ask if someone could give me a clue.

Thanky.

cgraz

What are you trying to do? I found an old post where some guy wanted to link next and previous using his id in the variable, but had the same problem: the id's weren't in order . Anyways, don't know what you're trying to do (and count has never been my strong point), but here's the code I gave him

<?

// make sure to add your db connection and select your db

// also change $table to your table name
$query = "SELECT eid FROM $table";
$result = mysql_query($query);

// set starting value (don't change)
$row2 = "";

// add \n so that you can later convert to array
while($row = mysql_fetch_array($result)) {
  $row2 .= $row["id"] . "\n";
}

// create array
$row2 = explode("\n", $row2);

// delete last value which is empty
array_pop($row2);

// set these values to what you want. You can delete them and do this dynamically later
$eid = "5";
$direction = "forward";

if ($direction == 'forward') {
   // $key will return the corresponding key for where you are currently at
   $key = array_search($eid, $row2);
      echo "Currently At: " . $row2[$key] . "<br>\n";
   // will go to the next key
   $key = $key + 1;
      echo "Next id in DB " . $row2[$key] . "<br>\n";

} elseif ($direction == 'backwards') {
   // $key will return the corresponding key for where you are currently at
   $key = array_search($eid, $row2);
      echo "Currently At eid: " . $row2[$key] . "<br>\n";
   // will go to the previous key
   $key = $key - 1;
      echo "Previous eid in DB " . $row2[$key] . "<br>\n";

}


?>

Ofcourse his field was eid, not id. I wrote this a while back; there's prob an easier way to do this, this is just what I came up with.

Cgraz

theDog

Actually, it was a simple index of websites, and then the index got big and wanted sorting and searched, so i made it into a database thingy, and i thought hey why not make it a web ring too? So i did.

The thing is, being n00b and all, i didn't think hard enough. What happens is when they sign up for the index, they're assigned a number. If, e.g., their site is #4, when someone clicks the "next" link on their page, this script sends them to site #5. And viceversa for "last." And of course, if they come from the last URL, then they go to the first one, which i was smart enough to use count() for that.

But now i can't delete sites from the index.

Is there a way to fetch a numerically ordered array from the ID column? Or is that what you're showing me? I can't quite decipher it atm.

I shouldn't drink and post.

theDog

Or, what about if there is no ID #6, the script keeps looking for the next highest number? Could i do that with a while loop?

cgraz

If there is no id 6, the script takes care of that.

If puts all the id's into an array, finds out where you are, then if you want to go to the next id, it goes to the next array key (which holds the value of the next id). going backwards works the same, except it goes the previous array key.

Copy and paste, replace your mysql info (and change eid to id), and play with it. You'll see how it works.

Cgraz

theDog

Thanks, i thought it might. Learning as i go, and don't recognize some those functions.

Not sure i should be playing with something called explode() but here goes...

:eek: