为什么map函数会改变perl中输入数组的值？

Question

为什么map函数会改变perl中输入数组的值？ 为了说明，

#!/usr/bin/env perl


use strict;
use warnings;
use v5.10;


my @words = <DATA>;

# want to have another array that contains the each word in reverse order
my @reverse_words =  map {  $_   =  scalar reverse $_    } @words;

say $words[0]; # want to check the content of first element of original array
say $reverse_words[0]; # new 



__DATA__
aarhus
aaron
ababa
aback

但这打印

 $perl findPalindrome.pl

suhraa

suhraa

为什么原始数组会改变？

Answer 1

因为您通过修改$_来询问它。

你想要

my @reverse_words = map { scalar reverse $_ } @words;