Question

    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.
    Use of uninitialized value $_ in string at /usr/local/share/perl/5.20.2/Mojo/Collection.pm line 45.

这在mojolicious的背景下意味着什么？我假设在呈现html页面时存在某种格式不正确的字符串。非常感谢任何帮助。

sub join { Mojo::ByteStream->new(join $_[1] // '', map {"$_"} @{$_[0]}); }

这是mojolicious源代码中的一行，但我相信它会被我的html文件中的某些内容触发，我将免去你看到的痛苦。

Answer 1

您不需要使用＆＃39; map＆＃39;。 join将采用数组。

很明显你的子书写的是这样的：

sub join {
    my $list = shift;
    my $sep  = shift // '';
    Mojo::ByteStream->new( join( $sep, @$list ) );
}

转储所有变量，查看其中的内容。
万一你从未使用过Data :: Dumper，请执行以下操作：
```
use Data::Dumper;
print Dumper($list);
```
BTW，Mojolicious中包含dumper方法。 $c->dumper( $your_var )

在字符串中使用未初始化的值$ _ - mojolicious perl

1 个答案: