Perl MindMelting来自数组异常的标量中的未初始化变量(Perl MindMelting uninitialized variable in scalar from array excep

Perl MindMelting来自数组异常的标量中的未初始化变量(Perl MindMelting uninitialized variable in scalar from array exception)

我很难说出这个问题，因为我真的难以理解可能导致这个错误的原因。

当我输入这样的代码时：

my @strArray= ('TypeKey', 'AccidentType', '01'); my %HashArrayThing = ('EnglishArray' => @strArray, 'FrenchArray' => ('julier', 'aout', 'septembre')); my $scalar = @HashArrayThing{EnglishArray}; my @ARR = @HashArrayThing{EnglishArray}; say $scalar, say $ARR[0];

输出是：

TypeKey TypeKey1

当我只改变say $ARR[0] say $ARR[1] （或任何其他数字）时，我得到错误：“在第50行说未初始化的值”（与'说$ scalar'相同的行）

这对我没有意义。 我可以理解$ ARR [1]可能超出范围，可能olny从存储在hashset中的数组中获得了第一个值，但我完全不了解它的来源。 我希望那里有一个人能够理解perl谁可以启发我。

PS。 同样来自'1'的地方是bieng添加到typekey。

I had a hard time titleing this question, as I am truly stumped as to what could be causing this error.

when I have the code typed as such:

my @strArray= ('TypeKey', 'AccidentType', '01'); my %HashArrayThing = ('EnglishArray' => @strArray, 'FrenchArray' => ('julier', 'aout', 'septembre')); my $scalar = @HashArrayThing{EnglishArray}; my @ARR = @HashArrayThing{EnglishArray}; say $scalar, say $ARR[0];

the output is:

TypeKey TypeKey1

when I change ONLY the say $ARR[0] to say $ARR[1] (or any other number) I get the error: "Uninitialized value in say at line 50"(same line as the 'say $scalar')

This makes no sense to me. I could understand that the $ARR[1] could be out of bounds having maybe olny gotten the first value from the array stored in the hashset, but I don't understand at all where this is coming from. I hope there is someone out there with a thourough understanding of perl who can enlighten me.

PS. also where is the '1'coming from that is bieng added to typekey.

最满意答案

这一行：

my %HashArrayThing = ('EnglishArray' => @strArray, 'FrenchArray' => ('julier', 'aout', 'septembre'));

实际上是在创建这个结构：

( 'AccidentType' => '01', 'FrenchArray' => 'julier', 'EnglishArray' => 'TypeKey', 'aout' => 'septembre' )

我想象你在哪里：

( 'FrenchArray' => ['julier', 'aout', 'septembre'], 'EnglishArray' => ['TypeKey', 'AccidentType', '01'], )

发生这种情况是因为哈希中键/值对的值必须是SCALAR。 所以它是一个简单的值，如数字或字符串或对Hash或Array的引用 。

以下是初始化Hash的正确方法：

my %HashArrayThing = ( 'EnglishArray' => [@strArray], 'FrenchArray' => ['julier', 'aout', 'septembre'] );

请注意，先前传入的数组现在包含在[] ，这会创建对数组的引用。

This line:

my %HashArrayThing = ('EnglishArray' => @strArray, 'FrenchArray' => ('julier', 'aout', 'septembre'));

is actually creating this structure:

( 'AccidentType' => '01', 'FrenchArray' => 'julier', 'EnglishArray' => 'TypeKey', 'aout' => 'septembre' )

where I imagine you were expecting:

( 'FrenchArray' => ['julier', 'aout', 'septembre'], 'EnglishArray' => ['TypeKey', 'AccidentType', '01'], )

This is happening because the value of a key/value pair in a Hash must be a SCALAR. So it is a simple value like a number or a string or a reference to Hash or an Array.

The following is the correct way to initialize your Hash:

my %HashArrayThing = ( 'EnglishArray' => [@strArray], 'FrenchArray' => ['julier', 'aout', 'septembre'] );

Notice that the arrays you passed in previously are now wrapped in [] which creates a reference to an array.