using if, else and elseif statements

morpheusoptic

Hello, I have been designing basic HTML webpages for a few years now and am very proficient in HTML. However because of its limitations with database connections and form processing, I have decided to start using PHP.

I am making a registrations script for users to add a free classified to my classifieds section of my website, the registration page will be 3 pages long, but in actuality, it will be just one page with functions that contain the next page being called after each form is submitted.

I am having trouble trying to call the third page, I can get the first and second page to display but not the third, let me give you an example of my code.

<?php

require_once('fns.php');

if (empty($POST)) { sellerad1(); } // Contains the HTML for this form
elseif ($POST) { sellerad2(); } // Contains the HTML for this form
else ($_POST) { postform(); }// Contains the HTML for this form

Obviously, they all use POST as the forms action.

in the elseif statement, is there any way to modify it so that it can check if $_POST contains information from sellerad2() only or what?

How can I make the postform() display after sellerad2() has been submitted?

Any help would be appreciated, I am new to this so please bare with me.

Thanks in advance,
Paul

planetsim

A typically if/elseif/else statement goes like so

if (expression)
{
  //statement
}
else if (expression)
{
  //statement
}
else
{
  //statement
}

You have added an expression on an else which you cannot do.

Try this instead

<?php

require_once('fns.php');

if (empty($_POST)) { sellerad1(); } // Contains the HTML for this form
elseif ($_POST) { sellerad2(); } // Contains the HTML for this form
else { postform(); }// Contains the HTML for this form

robert_w_ark

Your elseif code doesnt make sense - There is no clause in it...

(Seems weird, check this out..)

if(empty($POST)) // If post isnt empty.
{
sellerad1(); // Contains the HTML for this form
}
elseif($POST) // If post = True
/ Heres the problem, if it is a textbox, etc, how will it be true and pass? You should add a bit
more information such as elseif(($POST) != clause) - Confusing, lol /
{
sellerad2(); // Contains the HTML for this form
}
else($POST) // If theres no match.
{
postform(); // Contains the HTML for this form
}

Maybe its just me (Sorry, just woke up :o )

Edit: $_POST is an array by the way.

Example: $_POST['name_of_object_from_form'];

🙂

robert_w_ark

haha - i just noticed you are from bentonville, i live in rogers 🙂

rehfeld

actually, in this example, the else will never be reached


if (empty($_POST)) { sellerad1(); } // Contains the HTML for this form
elseif ($_POST) { sellerad2(); } // Contains the HTML for this form
else { postform(); }// Contains the HTML for this form

it is the same as this

if (empty($_POST)) { sellerad1(); } // Contains the HTML for this form
else { sellerad2(); }

either $POST is empty or its not. there is no third possibility here. if (empty($POST)) is exactly the same as doing if (!$_POST) with the exception that it will not generate a notice warning if the variable is non existant

you would likely want something like this


if (isset($_POST['field_from_form_1'])) {
    // do something
} elseif (isset($_POST['field_from_form_2'])) {
    // do something else
} else {
    // do default behavior when none of the above are ture
}

morpheusoptic

Thanks everyone for your replies.

I will try the examples and see what I can do with them. You have helped me understand why it wouldn't work which was my main goal.

Thanks again,

Paul

morpheusoptic

everyone, i'm back, lol

I tried the examples and they didn't work, so I tried making something else. I wonder if nesting if statements within eachother can make it work, however I am having no luck, it always only shows me the first page.

Please check my syntax and offer and corrections and suggestions.

<?php
  include ('fns.php');

  if(sellerad1($_POST))
  {
    sellerad2();

if(sellerad2($_POST))
{
  postform();  
}
else
{
sellerad2();
}
  }
  /*else
  {
    sellerad1();  

  } */

/* FYI I am commenting out the else statement because if I use it as is, my sellerad1 form displays twice...  I doubt I need an else anyways.  */
?>

I am sure they need to be nested or something because if i just do a series of "if" and "else" statements, each form will still be displayed because it will still be true, especially in the (sellerad1($_POST)) case. After it has been posted, the php will still show it as valid and always show the form because that argument is true.

Robert, by the way, you said I should ad some validation.... I am going to implement that within each respective function.

Apparently I am doing something wrong, I think after I find out the correct way of using statements like this, PHP will be easier for me to understand.

Thanks in advance,
Paul

Roger_Ramjet

Looks to me like you need to learn about the 'Case Select' (generic term) control structure. All usefull programming languages have one, in PHP it is the Switch statement.

The first benefit of using switch is that your var need only be evaluated once, while it needs to be evaluated for each if in an if-elseif or nested if structure - saves lots of processor cycles.
It is also much more readable and therfore easier to code and debug.
The biggest advantage comes when you need to add a condition. With if-elseif or nested ifs, you sometimes have to completely reorder the logic: with switch you just add the new Case, no logic change needed.