如果在初始哈希定义中没有定义哈希键,有没有办法使perl编译失败
发布时间：2020-12-15 23:21:59 所属栏目：大数据 来源：网络整理
导读：使用的所有密钥都应存在于初始％哈希定义中. use strict;my %hash = ('key1' = 'abcd','key2' = 'efgh');$hash{'key3'} = '1234'; ## == I'd like for these to fail at compilation. $hash{'key4'}; ## == I'd like for these to fail at compilation. 有没
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使用的所有密钥都应存在于初始％哈希定义中.
use strict;
my %hash = ('key1' => 'abcd','key2' => 'efgh');
$hash{'key3'} = '1234'; ## <== I'd like for these to fail at compilation.
$hash{'key4'}; ## <== I'd like for these to fail at compilation.
有没有办法做到这一点？ 解决方法
自5.8.0以来,模块
Hash::Util已成为Perl的一部分.这包括一个’lock_keys’函数,它可以实现你想要的东西.如果您尝试将键添加到哈希,它会给出运行时(不是编译时)错误.
#!/usr/bin/perl
use strict;
use warnings;
use 5.010;
use Hash::Util 'lock_keys';
my %hash = (key1 => 'abcd',key2 => 'efgh');
lock_keys(%hash);
$hash{key3} = '1234'; ## <== I'd like for these to fail at compilation.
say $hash{key4}; ## <== I'd like for these to fail at compilation.
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