在Perl中定义类方法
其他面向对象的语言具有数据安全性的概念，以防止程序员直接更改对象数据，并且它们提供访问器方法来修改对象数据。Perl没有私有变量，但是我们仍然可以使用辅助方法的概念来操作对象数据。
让我们定义一个辅助方法来获取人的名字-
sub getFirstName {
return $self->{_firstName};
}另一个帮助者功能来设置人的名字-
sub setFirstName {
my ( $self, $firstName ) = @_;
$self->{_firstName} = $firstName if defined($firstName);
return $self->{_firstName};
}现在，让我们看一个完整的示例：将Person包和辅助函数保留在Person.pm文件中。
#!/usr/bin/perl
package Person;
sub new {
my $class = shift;
my $self = {
_firstName => shift,
_lastName => shift,
_ssn => shift,
};
# Print all the values just for clarification.
print "First Name is $self->{_firstName}\n";
print "Last Name is $self->{_lastName}\n";
print "SSN is $self->{_ssn}\n";
bless $self, $class;
return $self;
}
sub setFirstName {
my ( $self, $firstName ) = @_;
$self->{_firstName} = $firstName if defined($firstName);
return $self->{_firstName};
}
sub getFirstName {
my( $self ) = @_;
return $self->{_firstName};
}
1;现在，让我们如下使用employee.pl文件中的Person对象-
#!/usr/bin/perl use Person; $object = new Person( "Mohammad", "Saleem", 23234345); # Get first name which is set using constructor. $firstName = $object->getFirstName(); print "Before Setting First Name is : $firstName\n"; # Now Set first name using helper function. $object->setFirstName( "Mohd." ); # Now get first name set by helper function. $firstName = $object->getFirstName(); print "Before Setting First Name is : $firstName\n";
当我们执行以上程序时，它产生以下结果-
First Name is Mohammad Last Name is Saleem SSN is 23234345 Before Setting First Name is : Mohammad Before Setting First Name is : Mohd.