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PHP Tutorial >> Comments Using Comments in PHP
Comments in PHP are similar to comments that are used in HTML.
A comment is started with a special character sequence and all
text that appears between the start of the comment and the end will
be ignored by the browser.
In HTML, a comment's only purpose is to serve as a note to you, the web developer
or to others who may view your website's source. However, PHP's comments are different
in that they will not be displayed to your visitors. The only way to view PHP comments
is to open the file for editing, which makes PHP comments useful only PHP programmers.
In case
you forgot what an HTML comment looked like, see our example below.
HTML Code:
<!--- This is an HTML Comment -->
Single Line Comment
In HTML there was only one kind of comment. However, in PHP
there are two kinds. The first we will discuss is the single line
comment. The single line comment tells the interpreter to ignore
everything that occurrs on that line, to the right of the comment.
To do a single line comment type "//" and all
text that follows will be commented out.
PHP Code:
<?php
echo "Hello World!"; // This will print out Hello World!
echo "<br />Psst...You can't see my PHP comments!"; // echo "nothing";
// echo "My name is Humperdinkle!";
?>
Display:
Hello World!
Psst...You can't see my PHP comments!
Notice that a couple of our echo statements were not evaluated because we
commented them out with the single line comment.
This type of line commenting is often used for quick notes about
complex and confusing code or to temporarily remove a line of PHP code.
Multiple Line Comment
Similiar to the HTML comment, the multiple line PHP comment
can be used to comment out large blocks of code or writing multiple
line comments. The multiple line PHP comment begins with " /* " and ends
with " */ ".
PHP Code:
<?php
/* This Echo statement will print out my message to the
the place in which I reside on. In other words, the World. */
echo "Hello World!";
/* echo "My name is Humperdinkle!";
echo "No way! My name is Uber PHP Programmer!";
*/
?>
Display:
Good Commenting Practices
One of the best commenting practices that I can recommend to
new PHP programmers is....USE THEM!! So many people write complex
PHP code and are either too lazy to write good comments or believe
the commenting is not needed. However, do you really think that you
will remember exactly what you were thinking when looking at the code
a year or more later?
Let the comments permeate your code and you will be a happier PHPer
in the future. Use single line comments for quick notes about a tricky
part in your code and use multiple line comments when you need to describe
something in greater depth than a simple note.
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