PHP Variables
PHP Variable is the name of memory location used to hold the data. In PHP, variable starts with $ symbol.
Rules for PHP Variables.
- Variable starts with $ sign.
- Variable name must start with a letter or the underscore character.
- Variable name can contain alpha-numeric character (A-Z. 0-9).
- Variable name are case-sensitive ($name and $NAME are two different variables).
<?php $name = "RasmusLerdorf"; echo "PHP Father: $name"; ?>Output PHP Father: RasmusLerdorf In PHP, there are three variables:
- local variable
- global variable
- static variable
<?php
function fun() {
$x = 10; // local scope
echo "<p> x variable inside of the function: $x</p>";
}
fun();
// Generate an error because x is outside the function
echo "<p> x variable outside of the function: $x</p>";
?>
Output
x variable inside of the function: 10
Notice: Undefined variable: x in C:\xampp\htdocs\crud\HELLO.PHP on line 8
x variable outside of the function:
Global Variable
The Global is a keyword that is used to access global variable within a function.
Example:
<?php
$x = 10; // global variable
$y = 5; // global variable
$z=5; // global variable
function fun() {
global $x, $y,$z;
$y = $x * $y+$z;
}
fun();
echo $y; // outputs 55
?>
Output
55
Static variable
Php static is a keyword that is used to create a static variable. Static variable is not be deleted when a function is completed /executed.
Example
<?php
function fun() {
static $val = 0;
echo $val;
$val++;
}
fun();
echo "<br>";
fun(); // call function
echo "<br>";
fun(); // call function
echo "<br>";
?>
Output
0
1
2