Use base usage in Perl

Use base is object-oriented programming, used to describe the "base class", in fact, plainly,

Use base somemodule;
is equivalent to a combination of the following two sentences:

begin{
Use Somemodule ();
Push @ISA, QW (Somemodule);
}
You can also use base two or more than two modules at a time, for example:

Use base QW (Foo Bar);
is equivalent to:

BEGIN {
Use Foo ();
Use Bar ();
Push @ISA, QW (Foo Bar);
}
As to what kind of array @ISA is, it's completely off the use base.
However, @ISA is a special array, and its meaning can be found in the description of the big camel.

By the way,


Use Foo ();
And
Use Foo;
is different,
The latter automatically calls the Import function in the Foo package, which does not.

Use base somemodule;
Than
Use Somemodule;
And there's just one more sentence.
Push @ISA, QW (Somemodule);

Reprint: http://blog.csdn.net/zll01/article/details/4520237