PHP Variables
A variable is used to store information.
Variables in PHP
Variables are used for storing a values, like text strings, numbers or
arrays.
When a variable is declared, it can be used over and over again in your script.
All variables in PHP start with a $ sign symbol.
The correct way of declaring a variable in PHP:
New PHP programmers often forget the $ sign at the beginning of the
variable. In that case it will not work.
Let's try creating a variable containing a string, and a variable containing a number:
<?php
$txt="Hello World!";
$x=16;
?>
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PHP is a Loosely Typed Language
In PHP, a variable does not need to be declared before adding a value to it.
In the example above, you see that you do not have to tell PHP which data
type the variable is.
PHP automatically converts the variable to the correct data type, depending
on its value.
In a strongly typed programming language, you have to declare (define) the
type and name of the variable before using it.
In PHP, the variable is declared automatically when you use it.
Naming Rules for Variables
- A variable name must start with a letter or an underscore "_"
- A variable name can only contain alpha-numeric characters and underscores
(a-z, A-Z, 0-9, and _ )
- A variable name should not contain spaces. If a variable name is more than one word,
it should be separated with
an underscore ($my_string), or with capitalization ($myString)
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