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  man pages->IRIX man pages -> perl5/UNIVERSAL (3)              



NAME    [Toc]    [Back]

     UNIVERSAL - base class for	ALL classes (blessed references)

SYNOPSIS    [Toc]    [Back]

	 $io = $fd->isa("IO::Handle");
	 $sub =	$obj->can('print');

	 $yes =	UNIVERSAL::isa($ref, "HASH");

DESCRIPTION    [Toc]    [Back]

     UNIVERSAL is the base class which all bless references will inherit from,
     see the perlobj manpage

     UNIVERSAL provides	the following methods

     isa ( TYPE	)
	 isa returns true if REF is blessed into package TYPE or inherits from
	 package TYPE.

	 isa can be called as either a static or object	method call.

     can ( METHOD )
	 can checks if the object has a	method called METHOD. If it does then
	 a reference to	the sub	is returned. If	it does	not then undef is

	 can can be called as either a static or object	method call.

     VERSION ( [ REQUIRE ] )
	 VERSION will return the value of the variable $VERSION	in the package
	 the object is blessed into. If	REQUIRE	is given then it will do a
	 comparison and	die if the package version is not greater than or
	 equal to REQUIRE.

	 VERSION can be	called as either a static or object method call.

     The isa and can methods can also be called	as subroutines

     UNIVERSAL::isa ( VAL, TYPE	)
	 isa returns true if the first argument	is a reference and either of
	 the following statements is true.

		 VAL is	a blessed reference and	is blessed into	package	TYPE
		 or inherits from package TYPE

		 VAL is	a reference to a TYPE of perl variable (er 'HASH')

	 If VAL	is a blessed reference which has a method called METHOD, can
	 returns a reference to	the subroutine.	  If VAL is not	a blessed
	 reference, or if it does not have a method METHOD, undef is returned.

									Page 1


     These subroutines should not be imported via use UNIVERSAL	qw(...).  If
     you want simple local access to them you can do

       *isa = \&UNIVERSAL::isa;

     to	import isa into	your package.

									PPPPaaaaggggeeee 2222
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