面向对象之继承篇

Bean.pm  (父类)

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package Bean;

require Exporter;

@ISA=qw(Exporter);

@EXPORT=qw(setBeanType);

sub new{

  my $type=shift;

  my $this={};

  $this->{'Bean'}='Colombian';

  bless $this,$type;

  return $this;

}

sub setBeanType{

  my($class,$name)=@_;

  $class->{'Bean'}=$name;

  print "Set Bean to $name \n";

}

1;

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Coffee.pm  (子类)

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package Coffee;

require Exporter;

use Bean;

@ISA=qw(Exporter Bean);

@EXPORT=qw(setBeanType setCoffeeType);

sub setCoffeeType{

  my($class,$name)=@_;

  $class->{'Coffee'}=$name;

  print "set Coffee type to $name \n";

}

sub new{

  my $type=shift;

  my $this=Bean->new();

  $this->{'Coffee'}='instant';

  bless $this,$type;

  return $this;

}

1;

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继承案例

#!/usr/bin/perl

push(@INC,`pwd`);

use Coffee;

$cup=new Coffee;

print $cup->{'Coffee'};

print "\n";

print $cup->{'Bean'};

print "\n";

$cup->setBeanType('Mixed');

$cup->setCoffeeType('mmmm');

补充资料:

@INC 是由use,require在加载模块时所搜寻的路径.

@ISA  perl类的继承是通过@ISA数组实现的.@ISA数组不需要在任何包中定义,然而,一旦被定义,perl就把它看作目录名的特殊数组.它与@INC数组类似,@INC是包含文件的寻找路径.@ISA数组含有类(包)名,当一个方法在当前包中未找到时,就可以到@ISA中的包去寻找.@ISA中还含有当前类继承的基类名.