Function definition
A function is a body of code that returns a value. The value returned may depend on arguments provided to the function.
![Task](http://static.miraheze.org/rosettacodewiki/thumb/b/ba/Rcode-button-task-crushed.png/64px-Rcode-button-task-crushed.png)
You are encouraged to solve this task according to the task description, using any language you may know.
Write a definition of a function called "multiply" that takes two arguments and returns their product.
C
double multiply( double a, double b ) { return a * b; }
Perl
sub multiply( $$ ) { $a = shift; $b = shift; return $a * $b; }
{header|PHP}
function multiply( $a, $b ) { return $a * $b; }