排骨澄清

本文介绍了排骨澄清的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我现在正在放假，决定花时间学习Perl.我正在使用Beginning Perl( http://www.perl.org/books/beginning- perl/)，我将在第三章结尾处完成练习.

I'm on break from classes right now and decided to spend my time learning Perl. I'm working with Beginning Perl (http://www.perl.org/books/beginning-perl/) and I'm finishing up the exercises at the end of chapter three.

其中一项练习要求我将您的重要电话号码存储在哈希中.编写一个程序，以该人的姓名查找号码."

One of the exercises asked that I "Store your important phone numbers in a hash. Write a program to look up numbers by the person's name."

无论如何，我想出了这个:

Anyway, I had come up with this:

#!/usr/bin/perl
use warnings;
use strict;

my %name_number=
(
Me => "XXX XXX XXXX",
Home => "YYY YYY YYYY",
Emergency => "ZZZ ZZZ ZZZZ",
Lookup => "411"
);

print "Enter the name of who you want to call (Me, Home, Emergency, Lookup)", "\n";
my $input = <STDIN>;
print "$input can be reached at $name_number{$input}\n";

那是行不通的.我不断收到此错误消息:

And it just wouldn't work. I kept getting this error message:

我尝试了一些更多的代码，但是每个解决方案"看起来都比之前的解决方案"复杂.最后，我决定检查答案.

I tried playing around with the code some more but each "solution" looked more complex than the "solution" that came before it. Finally, I decided to check the answers.

我的代码和答案之间的唯一区别是在<STDIN>;之后出现了chomp ($input);.

The only difference between my code and the answer was the presence of chomp ($input); after <STDIN>;.

现在，作者在先前的示例中使用了chomp，但是他并没有真正涵盖chomp的工作.因此，我在www.perlmeme.org上找到了这个答案:

Now, the author has used chomp in previous example but he didn't really cover what chomp was doing. So, I found this answer on www.perlmeme.org:

无论如何，我的问题是:

Anyway, my questions are:

正在删除哪些换行符? Perl是否会自动将"\n"附加到<STDIN>的输入中?我只是有点不清楚，因为当我读到它实际上删除了与$/的当前值匹配的任何字符"时，我不禁想到我不记得在代码中的任何地方放置$/了" ."

What newlines are getting removed? Does Perl automatically append a "\n" to the input from <STDIN>? I'm just a little unclear because when I read "it actually removes any character that matches the current value of $/", I can't help but think "I don't remember putting a $/ anywhere in my code."

我想尽快制定最佳实践-是始终在<STDIN>之后始终包含chomp还是在不必要的情况下?

I'd like to develop best practices as soon as possible - is it best to always include chomp after <STDIN> or are there scenarios where it's unnecessary?

chomp

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