如何在Perl中打印数组的所有值

Question

我试图从CSV文件打印数组的所有值.我在下面的例子中手动执行此操作.有人可以向我展示为阵列的所有字段执行此操作的代码,无论有多少字段？我基本上只是想在一个新行上打印每个字段.

#!/usr/bin/perl
use strict;
use warnings;
use Text::CSV_XS;

my $file = 'test.csv';

my $csv = Text::CSV_XS->new ({
    quote_char          => '"',
    escape_char         => '@',
    binary              => 1,
    keep_meta_info      => 0,
    allow_loose_quotes  => 1,
    allow_whitespace    => 1,
});


open (CSV, "<", $file) or die $!;

while (<CSV>) {
    if ($csv->parse($_)) {
        my @columns = $csv->fields();
        print "$columns[0]\r\n";
        print "$columns[1]\r\n";
        print "$columns[2]\r\n";
        print "$columns[3]\r\n";
        print "$columns[4]\r\n";
        print "$columns[5]\r\n";
        print "$columns[6]\r\n";
        print "$columns[7]\r\n";
    }
    else {
        my $err = $csv->error_input;
        print "Failed to parse line: $err";
    }
}
close CSV;

Answer 1

foreach(@columns)
{
    print "$_\r\n";
}

而不是所有列[数字].

Answer 2

出于调试目的,Data::Dump是我的首选武器.它基本上可以打印数据结构.

use strict;
use warnings;
use Data::Dump 'dump';

# Do some stuff....

dump @array;     # Unlike Data::Dumper, there's no need to backslash ('\@array')
dump %hash;      # Same goes for hashes
dump $arrayref;  
dump $hashref;   # References handled just as well

当然,还有许多其他方法可以打印数组:

say foreach @columns;           # If you have Perl 5.10+
print $_,"\n" foreach @columns; # If you don't

print "@columns";               # Prints all elements, space-separated by default

"最佳"答案取决于具体情况.你为什么需要它？你在忙什么？你想要它做什么？然后相应地调整代码.

Answer 3

如果您只想打印由空格分隔的元素:

print @columns;

如果你想要更加花哨,你可以使用join:

print join("\n", @columns);

如果您需要做更多的事情,请迭代它:

foreach (@columns) {
    # do stuff with $_
}