PHP Forum

**ericson3000** · 05-30-2010, 09:12 PM

I know that you can put PHP code inside HTML so long as it is enclosed in the <?php ... ?>

Also, you can keep the code in an external PHP document.

However, I have been told that PHP code can be placed in a document before the <!DOCTYPE>. Is this true, or like JavaScript, should it simply be placed in the <head>. The code will be used for a form on the page.

**NullPointer** · 05-30-2010, 09:27 PM

All client side code (HTML, javascript, CSS) is completely distinct from server side code (PHP in this case). It does not matter if you put PHP code before or after the doctype, because PHP is not aware of any particular markup that you are using, just as client side code is completely unaware of server side code.

HTML is the output of your PHP script.

**ericson3000** · 05-30-2010, 09:29 PM

Thanks for the clarification. Appreciate it.

**Arings** · 05-31-2010, 09:32 AM

Quote:

Originally Posted by ericson3000

I know that you can put PHP code inside HTML so long as it is enclosed in the <?php ... ?>

Also, you can keep the code in an external PHP document.

However, I have been told that PHP code can be placed in a document before the <!DOCTYPE>. Is this true, or like JavaScript, should it simply be placed in the <head>. The code will be used for a form on the page.

PHP is a server site script while HTML or Javascript is client side scripting language. So it really doesn't matter where you are placing your script. But as a good programmer you should always try to make best use of compiler and interpreter. So the pages where we require session check or some security check then it is better to include the PHP codes in the beginning, so that in case of failure checking the value the url can be redirected without interpreting the HTML version below it.

So it's up0 to you where you would like to use <?php ?>

**chrishirst** · 05-31-2010, 09:46 AM

Quote:

So it's up0 to you where you would like to use <?php ?>

That's a very broad statement and as such is incorrect..

IF the PHP code is delivering output as content, it MUST be placed in the document where the content is intended to be displayed.
If the PHP code is to deliver a header response to the user agent (redirect or similar) it MUST be before any output is sent to the user agent.

Whatever the PHP script is actually doing it has to be at an appropriate location in the document.

**joyhitech** · 05-31-2010, 10:14 AM

In my experience i can place php code before <!DOCTYPE> it well

**lynxus** · 05-31-2010, 11:02 AM

Quote:

Originally Posted by joyhitech

In my experience i can place php code before <!DOCTYPE> it well

As chris has said, You CAN place it where the hell you like.

However, It can only be placed in certain places depending on what you want the outcome of your script to do...

So the answer in a broader sense is, Yes and No

**Marik** · 05-31-2010, 12:44 PM

Sometimes you can tell when PHP (or some other server side code) has been placed before the doctype when you view the source of a page and find that the HTML starts a few lines below one or more empty lines.

Even though PHP code as a server side language will never display itself in a page's source code it will still take up empty lines in the source (if it's the type of code that doesn't have any output to occupy it's place).

**Marik** · 05-31-2010, 12:48 PM

Quote:

Originally Posted by chrishirst

That's a very broad statement and as such is incorrect..

IF the PHP code is delivering output as content, it MUST be placed in the document where the content is intended to be displayed.
If the PHP code is to deliver a header response to the user agent (redirect or similar) it MUST be before any output is sent to the user agent.

Whatever the PHP script is actually doing it has to be at an appropriate location in the document.

Agreed, and of course the obvious chronological order of commands must be followed for a script to work properly. This won't work:

PHP Code:


			

echo $name;

$name = 'Mike';