类似数组格式的多个标准输入

Question

我需要让我的代码产生以下输出，但我无法让它工作。

示例程序输出

Please enter your 3 numbers: 12 45 78
Your numbers forward: 
12 
45 
78 
Your numbers reversed: 
78 
45 
12

我的 Perl 代码

#!/usr/bin/perl

#use strict;
use warnings;
use 5.010;

print "Please enter your 3 numbers: \n";
my $n1 = <STDIN>;
my $n2 = <STDIN>;
my $n3 = <STDIN>;

print "Your numbers forward: \n";
print $n1;
print $n2;
print $n3;

#Possible Backup Idea
# my @names = (n1, n2, n3);
# foreach my $n (@names) {
#   say $n;
# }

#2nd Possible Backup Idea
# print "$coins[0]\n"; #Prints the first element
# print "$coins[-1]\n"; #Prints the last element
# print "$coins[-2]"; #Prints 2nd to last element

print "Your numbers reversed: \n";
print $n3;
print $n2;
print $n1;

但是当它运行时，它不会像我一样在一行中接受所有输入需要，必须输入3次才能生效。

Please enter your 3 numbers: 
12
23
34
Your numbers forward: 
12
23
34
Your numbers reversed: 
34
23
12

Answer 1

my $n1 = <STDIN>; 一次读一整行。所以重复三次将读取三行。

相反，您想读取一行，然后 split 将其放在空白处变成数字数组。

my $input = <STDIN>;
my @numbers = split /\s+/, $input;

/\s+/ 是匹配任意数量的空白字符的正则表达式。有关更多信息，请参阅 Perl Regex Tutorial。

然后您可以使用 for loops.

处理数字列表

print "Your numbers forward:\n";
for my $number (@numbers) {
    print "$number\n";
}

print "Your numbers reversed: \n";
for my $number (reverse @numbers) {
    print "$number\n";
}

Answer 2

您可以使用 stdin 获取输入，但您需要根据 space 字符作为分隔符进行拆分。

#!/usr/bin/perl
use warnings;
use strict;
use feature qw(say);

say "Pick 3 numbers";
my $input = <STDIN>;
my @numbers = split(/\s+/, $input);
my @reverse_numbers = reverse(@numbers);


say "Your numbers forward:";
say join("\n", @numbers);
say "Your numbers backwards:";
say join("\n", @reverse_numbers);

类似数组格式的多个标准输入

Multiple standard input in array-like format

arrays

perl

stdin

input

示例程序输出

我的 Perl 代码