Perl untie 函数

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  描述

  untie此函数打破了变量和包之间的绑定，从而取消了tie函数创建的关联。
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  句法

  以下是此函数的简单语法-

  
  untie VARIABLE
  

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  返回值

  如果失败，此函数返回0，如果成功，则返回1。
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  示例

  以下是显示其基本用法的示例代码-

   
  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.
  

  尝试一下

  执行以上代码后，将产生以下结果-

  
  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