即使在perl的while循环中声明了数组，也无法访问数组

Question

I'm trying to read a CVS file to fetch 2nd and 3rd column in it. I have declared empty array @x_ax and @dat outside the while loop. I'm using @x_ax to store 2nd column and @dat to store 3rd column of CSV file. Contents of @x_ax and @dat is getting printed inside while loop only but not outside.

below is my code and output.

#!/usr/bin/perl
use strict;

my @arr=();
my @x_ax=();
my @dat=();
open(FH,"new1.csv") || die "Not able to open new1.csv file $!\n";

while( my $line=<FH>)
{
        if ($line =~ m/Time/)
        {
                exit 0;
        }
        else
        {
                @arr=split(/,/,$line);
                #print "@arr[1]\n";
                push(@x_ax,$arr[1]);
                print "@x_ax \n";
                push(@dat,$arr[2]);
        }
}

print @x_ax;
print "$#x_ax and $#dat \n";

[root@localhost perl_practice]# perl test.pl 
AX_1 
AX_1 SAL 
AX_1 SAL BAS 
AX_1 SAL BAS OPT 
AX_1 SAL BAS OPT LES 
AX_1 SAL BAS OPT LES MSS

below is my CSV file contents

17:00:01,AX_1,0,0,0,0,0
17:00:01,SAL,0,0,0,0,0
17:00:01,BAS,0,0,0,0,0
16:55:02,OPT,0,0,0,0,0
17:00:01,LES,0,0,0,0,0
16:55:02,MSS,0,0,0,0,0
Time,info,dat1,dat2,dat3,dat4,dat5

How to access @x_ax and @dat outside while loop?.

Answer 1

It's not that you can't access them outside the array, the problem is that your program never reaches those last print statements. As you have:

if ($line =~ m/Time/)
{
    exit 0;
}

And the last line of your CSV has Time , the program exits before reaching the final print.

If you meant the if statement to stop the loop only, you can use last . Then the else itself is not needed as well, becoming a more common loop idiom:

while( my $line=<FH>)
{
    last if ($line =~ m/Time/);

    @arr = split(/,/,$line);
    #print "@arr[1]\n";
    push(@x_ax,$arr[1]);
    print "@x_ax \n";
    push(@dat,$arr[2]);
}