PHP is an HTML-embedded
server-side scripting language. When building a complex page, at some point you
will be faced with the need to combine PHP and HTML to achieve your needed
results. At the first point, this can seem complicated, since PHP and HTML are two
separate languages, but this is not the case. PHP is designed to interact with
HTML and PHP scripts can
be included in an HTML page without a problem.
In an HTML page, PHP code is
enclosed within special PHP tags. When a visitor opens the page, the server
processes the PHP code and then sends the output (not the PHP code itself) to
the visitor's browser. Actually, it is quite simple to integrate HTML and PHP. A
PHP script can be treated as an HTML page, with bits of PHP inserted here and
there. Anything in a PHP script that is not contained within <?php ?> tags
is ignored by the PHP compiler and passed directly to the web browser. If you
look at the example below you can see what a full PHP script might look like:
Recommended usage:
The code above is simply
HTML, with just a bit of PHP that prints out today's date using the built-in
date function. As mentioned above, all of the plain HTML in the code above will
be ignored by the PHP compiler and passed through to the web browser untouched.
More advanced techniques:
and the result is:
PHP
in HTML using short_open_tag
If you want to shorten your
code as much as possible, you can go for the short_tags option. This will save
you from typing <?php at
the beginning of the code, shortening it to just <?.
PHP in HTML using
short_tags:
Have in mind that if you
want to build a website compatible with as many platforms as possible, you
should not rely on short_tags.
HTML in PHP using echo
A possible way to integrate
HTML tags in a PHP file is via the echo command:
Possible yet not recommended
usage:
This will, however, affect
the HTML Code Coloring option in most HTML/PHP editors, which allows for an easy
understanding of the role of HTML tags. You should escape each double quote
within the HTML code with a backslash.
Comments in PHP
The
word comment itself expresses its meaning as commenting out something. If we
comment on anything in the PHP program file, it will not be compiled with the
code. The compiler or the interpreter will simply ignore this.
There are two types of comments you can
add:
1. Single line comment used for quick notes about complex code or to temporarily disable a line of PHP code. You need to add // or # before the code.
Example-1 :
<?phpecho "This is my first PHP Program";// this is the first program?>
Example-2 :
<?php# $i=10;# $j=20;# echo $i + $j;echo "Hello World!";# this is PHP comment?>
2. Multi-line comment used to comment out large blocks of code or writing multiple line comments. You need to add /* before and */ after the code.
Example: