WORKING WITH VARIABLES AND CONSTANTS
Learning Objectives
At the end of
this topic, you will be able to:
- Describe variables and constants Create and work with variables and constants
- List the data types supported by PHP
- Use all the data types supported by PHP
- Describe all operators types supported by PHP
- Use all the operator types supported by PHP
Variables in PHP
- Variables are used to store information.
- Naming convention:
- Variables in PHP are denoted by a $ sign followed by a variable name
- Variable names must begin with a letter or an underscore character
- Variable names must contain alpha-numeric characters or underscores
- Variable names must not contain spaces
- Variable names are case sensitive Variable names do not need to be declared in PHP
Working with
Variables
- Variables are assigned with the = operator, with the variable on the left-hand side and the expression to be evaluated on the right side
- Variables in PHP can be defined before they are assigned, but this is not mandatory
- Variables in PHP do not have intrinsic types, that is, a variable doesn't have to defined as an integer, or string. A variable can store any type of data
- Variables hold the most recent value that has been assigned to them
- Variables are created the moment a value is assigned to them
- Variables in PHP allows type conversion, if required
Examples:
$basic=2000;
$da=1000;
$total_salary=$basic+$da;
$message="Hello
world";
$avg=50.56;
Script:
Variable.php
Example: Working
with Variables
<?php
$msg="Hello";
$msg1="Kiran";
$a_number=4;
$anotherNumber=8;
$total=$a_number+$anotherNumber;
$msg2=$msg .
$msgl;
echo $msg2; echo
$total;
?>
Output
Hello Kiran
12
