Variables in PHP
Variables are like a container to store data.
Variables in php starts with Dollar sign ($).
Example:
$a = “Hello”;
$b = 50;
$c = 10.50;
?>
OUTPUT:
Hello
50
10.50
In the above example , there are 3 variables a,b,c which holds values “Hello”,”50″ and”10.50″ respectively.
Rules to declare a variable:
- A variable starts with the $ sign, followed by the name of the variable
- A variable name must start with a letter or the underscore character
- A variable name cannot start with a number
- A variable name can only contain alphanumeric characters and underscores (A-z, 0-9, and _ )
- Variable names are case-sensitive ($age and $AGE are two different variables)
Since PHP is a case-sensitive language make sure that your variables are properly used.
Printing the variable:
We use ‘echo’ or ‘print’ keyword to print a variable.
Example:
$a = “easyexamnotes.com”;
echo ” This is $a”;
?>
Scope of Variable:
PHP has three different variable scopes:
- Local
- Global
- Static
Global Variable:
A variable declared outside a function has a GLOBAL SCOPE and can only be accessed outside a function:
Example :
$a = 10; // global scope
function fun() {
// using x inside this function will generate an error
echo “Variable a in the function is: $a
“;
}
fun();
echo “Variable a outside function is: $a
“;
?>
OUTPUT :
Variable a in the function is:
Variable a outside function is: 50
Local Variable:
A variable declared within a function has a LOCAL SCOPE and can only be accessed within that function:
Example
function fun() {
$a = “Hii..”; // local scope
echo “Variable a in the function is: $a
“;
}
fun();
// using a outside the function will generate an error
echo “Variable a outside function is: $a
“;
?>
OUTPUT :
Variable a inside function is: Hii..
Variable a outside function is: