Creating a variable is also known as declaring it.
Declaring a variable is to use its name in your script:
When PHP first sees a variable's name in a script, it creates the variable at that point.
When declaring a variable in PHP, it's good practice to assign a value to it at the same time.
This is known as initializing a variable.
If you don't initialize a variable in PHP, it's given the default value of null .)
Here's an example of declaring and initializing a variable:
$my_first_variable = 3;
Here, the code creates the variable called $my_first_variable, and uses the = operator to assign it a value of 3.
The following script creates two variables, initializes them with the values 5 and 6 , then outputs their sum ( 11 ):
<?php $x = 5;//from w w w. jav a2 s. c o m $y = 6; echo $x + $y; ?>