PHP for Beginners: Basics, Syntax and Variables

A PHP scripting block always starts with <?php and ends with ?>. This scripting block can be placed anywhere in the document. A PHP file normally contains HTML tags along with some PHP scripting code. For example:

Each line of code in PHP must end with a semicolon which is a separator and is used to distinguish one set of instructions from another. In PHP, there are two basic statements to output text: echo and print.

In PHP, // is used for making a single-line comment, while /* and */ is used for block comment. The block comment can be single-line or multi-line:

Variables are used for storing values, like text strings, numbers or arrays. All variables in PHP start with a dollar sign ($) symbol and are declared as follows:

<?php $variable_name = value; ?>

Once a PHP variable is declared, it can be used over and over again in the script. Variables are case-sensitive, meaning that variable $name is not the same as variable $Name or $NAME. A variable does not need to be declared before setting it to a value. PHP sets the data type, depending upon the value. There are some rules when naming variables:

Rule 1: A variable name must start with a letter or underscore (“_”);
Rule 2: A variable name must only contain alpha-numeric characters and underscores (a-z, A-Z, 0-9, and “_”).

The following example shows the declaration of a string and number variable:

<?php
          $text_string = "string";
          $count = 10;
?>

String variables are used for variables that contain characters. A string can be used directly in function or it can be stored in a variable. The following example shows the declaration of a string variable:

<?php
          $msg = "Welcome to the Addictive Designs";
          echo $msg;
?>

This produces the following result:

Welcome to the Addictive Desings

Source from PHPpro Quick Guide