sub foo($$);

##</code><code>##

    sub foo($$);
    sub bar;

    bar "arg1", foo "arg2", "arg3", "arg4";

##</code><code>##

    bar("arg1", foo("arg2", "arg3"), "arg4");

##</code><code>##

    sub foo ($$);
    my @args = ("arg1", "arg2");
    foo @args;

##</code><code>##

    sub foo();           # Sub takes no arguments.
    sub foo($);          # Sub takes one argument.
    sub foo(&@);         # First argument is a block.
    sub foo(\@@);        # First argument will be reffed.

##</code><code>##

    sub bar;
    sub foo($);

    bar "arg1", foo "arg2", "arg3";