➤ Besides the built-in PHP functions, it is possible to create your own functions. • A function is a block of statements that can be used repeatedly in a program. • A function will not execute automatically when a page loads. • A function will be executed by a call to the function. ➤ A user-defined function declaration starts with the word function:

function
 functionName() {
  code to be executed;
}
functionName() // Calling a function

For instance:

function printMyName() {
	echo "My name is Levani :))\n";
}
printMyName(); // calling a function

➤ Function Arguments Information can be passed to functions through arguments. An argument is just like a variable. Arguments are specified after the function name, inside the parentheses. You can add as many arguments as you want, just separate them with a comma. For instance:

// Function with parameters
function printInfo($firstName,$lastName,$age){
	echo "Hello,my name is $firstName $lastName, I am $age years old :))\n";
}
// Arguments
printInfo("Levani","Makhareishvili",19);
$name = "Mads";
$lastName = "Mikkelsen";
$age = 56;
printInfo($name,$lastName,$age);

➤ Note the difference between parameters and arguments: • Function parameters are the names listed in the function's definition. • Function arguments are the real values passed to the function. • Parameters are initialized to the values of the arguments supplied. ➤ The advantages of using functions are: • Functions reduces the repetition of code within a program • Functions makes the code much easier to maintain • Functions makes it easier to eliminate the errors • Functions can be reused in other application