Rules for PHP variables:
1. A variable starts with the $ sign, followed by the name of the variable
2. A variable name must start with a letter or the underscore character
3. A variable name cannot start with a number
4. A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
5. Variable names are case sensitive ($y and $Y are two different variables)
The variables listed below are different variable:
$Name
$name
$NAME
$NAme
6. The variables in PHP are declared by appending the $ sign to the variable name.
For e.g
$company = “NCST”;
$sum = 10.0;
7. Variable data type is changed by the value that is assigned to the variable.
8. Type casting allows to change the data type explicitly.
9. Rich set of functions for working with variable.
For e.g.
gettype, settype, isset, unset, is_int, intvaletc etc
PHP Variables Scope
# PHP has three different variable scopes:
1. Local - A variable declaredwithina function
2. Global - A variable declaredoutsidea function
3. Static - When a function is executed, all of its variables are deleted. If you want a local variable NOT to be deleted, use thestatickeyword
Assignment Operator
• PHP assignment operator is “=“.
• Syntax of the assignment operator:
Variable = expression
Semantic of the assignment operator
– The right hand side expression to “=“ is computed and the result is assigned to the left hand side operand –assign by value
– In PHP assignment statement has a return value, which is the result of the expression on the right hand side.
