The real power of PHP comes from its functions.
PHP has more than 1000 built-in functions, and in addition, you can create your own custom functions to make your code modular and reusable.
A user-defined function declaration starts with the word function.
<?php
function writeMsg() {
echo "Hello world!";
}
writeMsg(); // Call the function
?>
Information can be passed to functions through arguments. An argument is just like a variable.
If you want a function to return a computed value back to you instead of printing it directly, use the return statement.
<?php
function sum($x, $y) {
$z = $x + $y;
return $z;
}
echo "5 + 10 = " . sum(5, 10);
?>