Perl 解除函式

描述

此函式打破變數與包之間的繫結，撤消 tie 函式建立的關聯。

語法

以下是此函式的簡單語法 −

untie VARIABLE

返回值

此函式在失敗時返回 0，在成功時返回 1。

示例

以下是顯示其基本用法的示例程式碼 −

#!/usr/bin/perl -w

package MyArray;

sub TIEARRAY {
   print "TYING\n";
   bless [];
}

sub DESTROY {
   print "DESTROYING\n";
}

sub STORE {
   my ($self, $index, $value ) = @_;
   print "STORING $value at index $index\n";
   $self[$index] = $value;
}

sub FETCH {
   my ($self, $index ) = @_;
   print "FETCHING the value at index $index\n";
   return $self[$index];
}

package main;
$object = tie @x, MyArray; #@x is now a MyArray array;

print "object is a ", ref($object), "\n";

$x[0] = 'This is test'; #this will call STORE();
print $x[0], "\n";      #this will call FETCH();
print $object->FETCH(0), "\n";
untie @x    		#now @x is a normal array again.

執行以上程式碼時，將產生以下結果 −

TYING
object is a MyArray
STORING This is test at index 0
FETCHING the value at index 0
This is test
FETCHING the value at index 0
This is test
DESTROYING