What are Object and Class in Perl?

PERLServer Side ProgrammingProgramming Scripts

There are three main terms, explained from the point of view of how Perl handles objects. The terms are object, class, and method.

  • An object within Perl is merely a reference to a data type that knows what class it belongs to. The object is stored as a reference in a scalar variable. Because a scalar only contains a reference to the object, the same scalar can hold different objects in different classes.
  • class within Perl is a package that contains the corresponding methods required to create and manipulate objects.
  • method within Perl is a subroutine, defined with the package. The first argument to the method is an object reference or a package name, depending on whether the method affects the current object or the class.

Perl provides a bless() function, which is used to return a reference which ultimately becomes an object.

Defining a Class

It is very simple to define a class in Perl. A class is corresponding to a Perl Package in its simplest form. To create a class in Perl, we first build a package.

A package is a self-contained unit of user-defined variables and subroutines, which can be re-used over and over again.

Perl Packages provide a separate namespace within a Perl program which keeps subroutines and variables independent from conflicting with those in other packages.

To declare a class named Person in Perl we do −

package Person;

The scope of the package definition extends to the end of the file, or until another package keyword is encountered.

raja
Published on 29-Nov-2019 16:48:19
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