Php Syntax with Example Tutorial

PHP - Syntax
Before we talk about PHP's syntax, let us first define what syntax is referring to.
• Syntax - The rules that must be followed to write properly structured code.
PHP's syntax and semantics are similar to most other programming languages (C, Java, Perl) with the addition that all PHP code is contained with a tag, of sorts. All PHP code must be contained within the following...


PHP Code:

?>
or the shorthand PHP tag that requires shorthand support to be enabled
on your server...

?>
If you are writing PHP scripts and plan on distributing them, we suggest that you use the standard form (which includes the ?php) rather than the shorthand form. This will ensure that your scripts will work, even when running on other servers with different settings.

How to Save Your PHP Pages
If you have PHP inserted into your HTML and want the web browser to interpret it correctly, then you must save the file with a .php extension, instead of the standard .html extension. So be sure to check that you are saving your files correctly. Instead of index.html, it should be index.php if there is PHP code in the file.
Example Simple HTML & PHP Page
Below is an example of one of the easiest PHP and HTML page that you can create and still follow web standards.

PHP and HTML Code:






echo "Hello World!";
?>


Display:
Hello World!

If you save this file and place it on PHP enabled server and load it up in your web browser, then you should see "Hello World!" displayed. If not, please check that you followed our example correctly.
We used the PHP function echo to write "Hello World!" and we will be talking in greater depth about this PHP function and many others later on in this tutorial.
The Semicolon!
As you may or may not have noticed in the above example, there was a semicolon after the line of PHP code. The semicolon signifies the end of a PHP statement and should never be forgotten. For example, if we repeated our "Hello World!" code several times, then we would need to place a semicolon at the end of each statement.


PHP and HTML Code:






echo "Hello World! ";
echo "Hello World! ";
echo "Hello World! ";
echo "Hello World! ";
echo "Hello World! ";
?>


Display:
Hello World! Hello World! Hello World! Hello World! Hello World!
White Space
As with HTML, whitespace is ignored between PHP statements. This means it is OK to have one line of PHP code, then 20 lines of blank space before the next line of PHP code. You can also press tab to indent your code and the PHP interpreter will ignore those spaces as well.


PHP and HTML Code:






echo "Hello World!";
echo "Hello World!";
?>


Display:
Hello World!Hello World!
This is perfectly legal PHP code.