1.Introduction to PHP

 1.       What is PHP?

–      is a general-purpose server-side scripting language originally designed for Web development to produce dynamic Web pages.

–      first developed server-side scripting languages to be embedded into an HTML source document rather than calling an external file to process data.

2.       PHP Basic Syntax Rules

–      PHP statements should be enclosed  with either of these php tags:

                <?php   ?>

                 <script language=“php”> </script>

                <?                           ?>

                 <%                         %>

–      Dynamic variable starts with a $(dollar sign)

–      PHP is case-sensitive.

–      Each statement ends with a semicolon.

–      To group statements, use curly braces.

–      To tell PHP that the statement is a comment, use either of these symbols.

–           // single line comment       /* multiline comments*/

Note: More rules as we go along.J

3.       PHP Program Structure

                 embedded structure

            <?php

                        //statements…..

            ?>

class structure

            <?php

                        class <classname>{

                                    //variables…

                                    //functions…     

                        }

            ?>

4.       Displaying  text on the screen

<?php

            echo “Hello World”;

 ?>

5.       Variable Data Types

A holder for a type of data.

–      numbers,

–      strings of characters,

–      objects,

–      arrays,

–      booleans.

Loosely typed

–      Takes the type of the value that is assigned to it

In PHP, you can assign value to a variable without declaring it.