Hello Friends.. In my Last Tutorial What Is PHP And Basic Tutorials For PHP Beginners You All read About the php now i am starting advanced level of PHP In which i ll tell about the PHP syntax and PHP Variables. As you all know that PHP is very popular now a days because Facebook.com and other big website are constructed using PHP and Some Other helping Languages i.e HTML, DHTML, XML And Etc.
Basic PHP Syntax:-
A PHP scripting block always starts with <?php and ends with ?>. A PHP scripting block can be placed anywhere in the document.
On servers with shorthand support enabled you can start a scripting block with <? and end with ?>.
For maximum compatibility, we recommend that you use the standard form (<?php) rather than the shorthand form.
A PHP file normally contains HTML tags, just like an HTML file, and some PHP scripting code.
Below, we have an example of a simple PHP script which sends the text “Hello World” to the browser:
Each code line in PHP must end with a semicolon. The semicolon is a separator and is used to distinguish one set of instructions from another.
There are two basic statements to output text with PHP: echo and print. In the example above we have used the echo statement to output the text “Hello World”.
Note: The file must have a .php extension. If the file has a .html extension, the PHP code will not be executed.
Comments in PHP
In PHP, we use // to make a single-line comment or /* and */ to make a large comment block.
//This is a comment/*
This is a commentblock
A variable is used to store information.
Variables in PHP
Variables are used for storing values, like text strings, numbers or arrays.
When a variable is declared, it can be used over and over again in your script.
All variables in PHP start with a $ sign symbol.
The correct way of declaring a variable in PHP:
|$var_name = value;|
New PHP programmers often forget the $ sign at the beginning of the variable. In that case it will not work.
Let’s try creating a variable containing a string, and a variable containing a number:
PHP is a Loosely Typed Language
In PHP, a variable does not need to be declared before adding a value to it.
In the example above, you see that you do not have to tell PHP which data type the variable is.
PHP automatically converts the variable to the correct data type, depending on its value.
In a strongly typed programming language, you have to declare (define) the type and name of the variable before using it.
In PHP, the variable is declared automatically when you use it.