Perl How to use array store input strings - arrays

Question

User first enter a number of lines. It then reads n lines of text from user input, and prints these lines backwards, i.e., if n=5, it prints the 5th
line first, the 4th, …, and the 1st,line last. I don't think wrong in my code, but when i start enter lines(line end with a newline), it won't stop. my array can store infinite number of lines which cause the problem stop them
use strict;
use warnings;
print "Enter number of n \n";
my $n = <STDIN>;
print "Enter couple lines of text \n";
my #array = (1..$n);
#array=<STDIN>;
do{
print "$array[$n]";
$n--;
}until($n=0);

Answer 1

Below are some tips that might help you:
Always include use strict; and use warnings at the top of your scripts to enforce good coding practices and help you find syntax errors sooner.
You must chomp your input from <STDIN> to remove return characters.
Use the array function push to add elements to the end of an array. Other relevant array functions include pop, shift, unshift, and potentially splice.
Use reverse to return an array of reversed order.
Finally, the for my $element (#array) { can be a helpful construct for iterating over the elements of an array.
These tips lead to the following code:
use strict;
use warnings;
print "Enter number of n \n";
chomp(my $n = <STDIN>);
die "n must be an integer" if $n =~ /^\d+$/;
my #array;
print "Enter $n lines of text\n";
for (1..$n) {
my $input = <STDIN>;
# chomp $input; # Do you want line endings, or not?
push #array, $input;
}
print "Here is your array: #array";

Answer 2

The end loop condition is do { … } until ($n = 0);, which is equivalent to do { … } while (!($n = 0));
The trouble is that the condition is an assignment, and zero is always false, so the loop is infinite.
Use do { … } until ($n == 0);.
Note that the input is in the line #array = <STDIN>; — it reads all the input provided until EOF. It is not constrained by the value of $n in any way.
#!/usr/bin/env perl
use strict;
use warnings;
print "Enter number of n \n";
my $n = <STDIN>;
printf "Got %d\n", $n;
print "Enter couple lines of text \n";
my #array = (1..$n);
#array = <STDIN>;
do {
print "$n = $array[$n]";
$n--;
} until ($n == 0);
When run, that gives:
$ perl inf.pl
Enter number of n
3
Got 3
Enter couple lines of text
abc
def
ghi
jkl
^D
3 = jkl
2 = ghi
1 = def
$
I think your expectations are skewiff.