A function has a name, arguments, and a block of code.
Optionally, it can return some value.
The name of the function has to follow the same rules as variable names.
It has to start with a letter or an underscore, and can contain any letters, numbers, or underscore.
The function's name cannot be a reserved word.
<?php function addNumbers($a, $b) { $sum = $a + $b; // w w w . j a va2 s .c o m return $sum; } $result = addNumbers(2, 3); ?>
Here, the function addNumbers takes two arguments: $a and $b.
The block of code defines a new variable $sum, which is the sum of both arguments, and then returns its content.
To use this function, call it by its name while sending all the required arguments.