Question about functions

3raser · April 4, 2011

Can someone give me an actual time when functions would become handy?

Thanks!

Philip · April 4, 2011

Now.

Maq · April 4, 2011

Can someone give me an actual time when functions would become handy?

Thanks!

Please, you can easily Google this for more reasons. Calling functions helps you not repeat code.

3raser · April 4, 2011

EDIT: I decided to post a question about functions instead.

Here is my function code:

<?php

function OverallGrabInfo($username)
{
$set_query = mysql_query("SELECT d.username, u.date, u.username FROM downloads d, users u WHERE d.username = '$username' AND u.username = '$username'") or die(mysql_error());

if(mysql_num_rows($set_query) == 0)

	$content_return = 'Sorry, no information was found';


else

	$grab = mysql_fetch_assoc($set_query);

	$content_return = $grab['date'];


return $content_return;
}

?>

Here is my page code:

<?php

if(!$_COOKIE['user'])
{
	$welcome = 'Welcome, guest! <a href="signup.php">Sign up now for uploading abilites!</a>';
}
else
{
	include_once('functions.php');
	$welcome = 'Welcome, '. $_COOKIE['user'] .'!'. $content_return;

}

?>

<html>
<head>
<link rel="stylesheet" type="text/css" href="style/style.css" />
<title><?php echo $title; ?></title>
</head>
<body>

<div class="logo"><a href="index.php"><img src="style/images/logo.png"></a></div>

<center>

<div class="background">

<div class="container">
Welcome.
</div>

</div>
</center>

</body>
</html>

How do I set $username to the one that will be processed in the function?

Maq · April 4, 2011

So submitting a post into a database would require a function?

Why, though? I mean, more code to do what you could do on the actual posting page...

Yes. You use functions all the time. mysql_query(...) is a function. Trust me, you wouldn't want to write that code every time. Native functions are used to reduce code, so are custom ones.

EDIT: Because you can ask questions on here. Thus the point of this whole section?

Because, unless you have a very specific question, then there are literally thousands of results for "PHP, why use functions?", and therefore, wasting our time.

.josh · April 4, 2011

you don't *need* functions, but they make life easier. The point of functions is being able to reuse code. If you just have a single page doing a single thing, then there is little point in making a function out of it. But if you have many pages doing the same thing, it makes more sense to make it into a function and call the same function - have a single instance of the code instead of many instances of it. Why? For one thing, having 100 instances of the same thing is a waste of space. Also, what about having to make updates to it? If you suddenly need to make a change to the code, you would be making a change to it in 100 places instead of one.

3raser · April 4, 2011

EDIT: I needed to make changes to the original post, like the one below, but couldn't edit. So I had to re-post, sorry for this.

Here is my function code:

<?php

function OverallGrabInfo($username)
{
$set_query = mysql_query("SELECT d.username, u.date, u.username FROM downloads d, users u WHERE d.username = '$username' AND u.username = '$username'") or die(mysql_error());

if(mysql_num_rows($set_query) == 0)

	$content_return = 'Sorry, no information was found';


else

	$grab = mysql_fetch_assoc($set_query);

	$content_return = $grab['date'];


return $content_return;
}

?>

Here is my page code:

<?php

if(!$_COOKIE['user'])
{
	$welcome = 'Welcome, guest! <a href="signup.php">Sign up now for uploading abilites!</a>';
}
else
{
	include_once('functions.php');
	$welcome = 'Welcome, '. $_COOKIE['user'] .'!'. $content_return;

}

?>

<html>
<head>
<link rel="stylesheet" type="text/css" href="style/style.css" />
<title><?php echo $title; ?></title>
</head>
<body>

<div class="logo"><a href="index.php"><img src="style/images/logo.png"></a></div>

<center>

<div class="background">

<div class="container">
Welcome.
</div>

</div>
</center>

</body>
</html>

How do I set $username to the one that will be processed in the function?

Maq · April 4, 2011

You would do something like this:

else
{
   include_once('functions.php');
   $content_return = OverallGrabInfo($_COOKIE['user']);
   $welcome = 'Welcome, '. $_COOKIE['user'] .'!' . $content_return;
}

FYI, your IF/ELSE blocks in your function are missing braces.

3raser · April 4, 2011

You would do something like this:
else
{
   include_once('functions.php');
   $content_return = OverallGrabInfo($_COOKIE['user']);
   $welcome = 'Welcome, '. $_COOKIE['user'] .'!' . $content_return;
}
FYI, your IF/ELSE blocks in your function are missing braces.

I was told that you can do if/else functions without braces, they said it could be an improvement for code. o.O

Maq · April 4, 2011

You would do something like this:
else
{
   include_once('functions.php');
   $content_return = OverallGrabInfo($_COOKIE['user']);
   $welcome = 'Welcome, '. $_COOKIE['user'] .'!' . $content_return;
}
FYI, your IF/ELSE blocks in your function are missing braces.
I was told that you can do if/else functions without braces, they said it could be an improvement for code. o.O

That only works if you want the block to only include the first line directly below it. It will throw a fatal error if you run it the way your blocks are set up.

3raser · April 4, 2011

You would do something like this:
else
{
   include_once('functions.php');
   $content_return = OverallGrabInfo($_COOKIE['user']);
   $welcome = 'Welcome, '. $_COOKIE['user'] .'!' . $content_return;
}
FYI, your IF/ELSE blocks in your function are missing braces.
I was told that you can do if/else functions without braces, they said it could be an improvement for code. o.O
That only works if you want the block to only include the first line directly below it. It will throw a fatal error if you run it the way your blocks are set up.

Thanks

This is now solved.

Maq · April 4, 2011

You would do something like this:
else
{
   include_once('functions.php');
   $content_return = OverallGrabInfo($_COOKIE['user']);
   $welcome = 'Welcome, '. $_COOKIE['user'] .'!' . $content_return;
}
FYI, your IF/ELSE blocks in your function are missing braces.
I was told that you can do if/else functions without braces, they said it could be an improvement for code. o.O
That only works if you want the block to only include the first line directly below it. It will throw a fatal error if you run it the way your blocks are set up.
Thanks

This is now solved.

You could have just hit the Auto Solve button ;P

3raser · April 4, 2011

Heh, I wish!

But yeah, one last question regarding functions (hopefully!). Here is my code below:

<?php

function OverallGrabInfo($username)
{
$set_query = mysql_query("SELECT COUNT(d.username), u.date, u.username FROM uploads d, users u WHERE d.username = '$username' AND u.username = '$username' LIMIT 1") or die(mysql_error());

if(mysql_num_rows($set_query) == 0)
{

	$content_return = 'Sorry, no information was found';

}
else
{
	$grab = mysql_fetch_assoc($set_query);

	//login information
	if($grab['COUNT(d.username)'] > 0)
	{
		$welcome_return = "You have uploaded ". $grab['COUNT(d.username)'] ." files. You've registered on ". $grab['u.date'] ."!";
	}
	else
	{	
		$welcome_return = "You have uploaded 0 files. You've registered on ".$grab['date'] . "!";
	}

	//display downloads


}	

return $content_return;
}
?>

Is it possible to grab information from $set_query without having the WHERE? I used the WHERE code to grab specific information regarding the user, but is it possible to do another section of the query to display all rows in the table uploads without having the WHERE? Or will I just need to create another query?

Maq · April 4, 2011

Now, when you call this function, unless you specify the $where parameter to be "FALSE", it will include the WHERE clause.

function OverallGrabInfo($username, $where=TRUE)
{
   if($where===TRUE)
   {
       $set_query = mysql_query("SELECT COUNT(d.username), u.date, u.username FROM uploads d, users u WHERE d.username = '$username' AND u.username = '$username' LIMIT 1") or die(mysql_error());
   }
   else
   {
      $set_query = mysql_query("SELECT COUNT(d.username), u.date, u.username FROM uploads d, users u") or die(mysql_error());
   }

3raser · April 4, 2011

Now, when you call this function, unless you specify the $where parameter to be "FALSE", it will include the WHERE clause.

function OverallGrabInfo($username, $where=TRUE)
{
   if($where===TRUE)
   {
       $set_query = mysql_query("SELECT COUNT(d.username), u.date, u.username FROM uploads d, users u WHERE d.username = '$username' AND u.username = '$username' LIMIT 1") or die(mysql_error());
   }
   else
   {
      $set_query = mysql_query("SELECT COUNT(d.username), u.date, u.username FROM uploads d, users u") or die(mysql_error());
   }

Ah, nice!

Also, if I were to make a sign-up/registration page, would creating another function for specifically that cut down on the code processing time? It's a one time code thing, though. So I'm not sure if I should create a function for it in functions.php, or just put the code on the signup.php page.

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