PHP - CODE For Beginner

What is PHP?

The acronym PHP initially stood for Personal Home Page.

As of version 3, it stands for PHP Hypertext Preprocessor. It is a general purpose server side scripting language that is used to develop:

Dynamic Websites

Custom Web Portal (Like ERP, CRM)

Web Applications

E-commerce Websites (Like Flipkart, Amazon, Paytm, Snapdeal etc)

CMS – Content Management System

Importance of PHP?

It costs low with cost effective database applications

It is platform independent

PHP supports all major web servers

The existence of multiple security layers make PHP one of the most secure options for developing the most critical websites and web applications.

PHP supports a wide array of databases including dataBase, MySQL etc.

History of PHP

Designed by Rasmus Lerdorf

Developer The PHP Development Team, Zend Technologies

First appeared June 8, 1995; 21 years ago

Stable release 7.1.0/ December 1, 2016

Basic Structure of PHP
<?php
//your code here
?>
Example:
<!doctype html>
 <html>
 <head><title>Hello World Script</title></head>
  <body>
  <?php
     echo "<p>Hello World!</p>";
   ?>
  </body>
 </html>
Printing statement in PHP

If you want to print/echo some string/variable or number in php
<?php 

$variable = "your string"; //

echo $variable; //

?>
File Extension of PHP
PHP files have the file extension .php
Comment Line in PHP

Single Line Comments

Single line comments start with //.

Any text between // and the end of the line will be ignored by PHP(will not be executed).

Example
echo 'This is a test'; // This is a one-line c++ style comment
Multi-line Comments

Multi-line comments start with /* and end with */.

Any text between /* and */ will be ignored by PHP.

Example
/* This is a multi line comment

          yet another line of comment */

/*  echo 'This is yet another test';

     echo 'Hi'; */

    echo 'One Final Test'; # This is a one-line shell-style comment
Variable Declaration

In PHP, a variable starts with the $ sign, followed by the name of the variable:

Example
<?php

$Vraiable_name = "Hello world!";

$x = 5;

$y = 10.5;

?>
A variable can have a short name (like x and y) or a more descriptive name (age, car name, total_volume).

Rules for PHP variables:

A variable starts with the $ sign, followed by the name of the variable

A variable name must start with a letter or the underscore character

A variable name cannot start with a number

A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )

Variable names are case-sensitive ($age and $AGE are two different variables)