PHP functions

A function is a block of code that can be executed whenever required. A function will be executed by a call to the function.
You may call a function from anywhere within a page. Give the function a name that reflects what the function does. The function name can start with a letter or underscore but not a number.
Syntax
function functionName()
{
code to be executed
}
Creating a simple function
<?php
function hello(){
echo “This is my first simple function”;
}
//call php function
hello();
?>

PHP function with parameters
<?php
function myHello($firstname)
{
echo “Namaste “. $firstName . “!<br />”;
}
//call function
myHello(“Ram”);
?>
Display:
Namaste Ram !
Another example
<?php
function addNumber($num1, $num2)
{
$num3= $num1+$num2;
echo “The sum is”.$num3;
}
//function call
addNumber(15,25);
?>