Perl `join` 生成多行字符串 [英] Perl `join` produces multi-line string

问题描述

我有这个程序来对两个数组进行排序

I have this program to sort two arrays

#!/usr/bin/perl -w

$movies = 'movies.txt';
open (FHD, $movies) || die " could not open $movies\n";
@movies = <FHD>;

$fruits = 'fruits.txt';
open (FHD, $fruits) || die " could not open $fruits\n";
@fruits = <FHD>;

@array3 = (@movies , @fruits);
@array3 = sort @array3;

print @array3;

当我运行它时，我得到了这样的东西

When I run it I get something like this

apple
gi joe
iron man
orange
pear
star trek
the blind side

我怎样才能把它改成这个样子?

How can I change it to look like this?

apple, gi joe, iron man, orange, pear, star trek, the blind side

我知道它与join有关，但是如果我将程序更改为此，它仍然会在多行上打印输出

I know it has something got to do with join, but if I change my program to this it still prints the output on multiple lines

$value = join(', ', @array3); 
print "$value\n";

推荐答案

数组中的数据在从文件中读取的每行末尾仍然有换行符.使用 chomp 来解决这个问题.

The data in the arrays still has the newline at the end of each line read from the file. Use chomp to fix this.

您还应该在每个 Perl 程序的顶部use strict 和use warnings.

You should also use strict and use warnings at the top of every Perl program.

最好的做法是使用词法文件句柄和三参数形式的open，并且您的 die 字符串应包含内置的 $! 变量说为什么打开失败.

It is best practice to use lexical file handles with the three-parameter form of open, and your die string should include the built-in $! variable to say why the open failed.

use strict;
use warnings;

my $movies = 'movies.txt';
open my $fh, '<', $movies or die "Could not open '$movies': $!\n";
my @movies = <$fh>;
chomp @movies;


my $fruits = 'fruits.txt';
open $fh, '<', $fruits or die "Could not open '$fruits': $!\n";
my @fruits = <$fh>;
chomp @fruits;

my @array3 = sort @movies, @fruits;

print join(', ', @array3), "\n";

输出

apple, gi joe, iron man, orange, pear, star trek, the blind side

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