How to print an array in upper case using tr///

Question

my @array = qw( one two three four five six seven );
my $arr = \@array;
# $arr=~ tr/,(a-z)/\t(A-Z)/;
print uc(join(' ', @array)), "\n";

output

ONE TWO THREE FOUR FIVE SIX SEVEN

But I want the same output using tr///.

Why would you want to use tr/// and have to know how to uppercase everything when uc() already knows that? — brian d foy, Dec 24 '13 at 21:13

mpapec · Accepted Answer · 2013-12-22T06:33:23.717

1

Replace (a-z) with a-z and perform tr/// for each element of @array

my @array = qw(one two three four five six seven);

tr/a-z/A-Z/ for @array;
print join(' ',@array), "\n";

edited Dec 22 '13 at 06:33

answered Dec 21 '13 at 07:05

mpapec

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Thanks for your answer.can you tell me, `->` why we use this operator in perl? – user3114045 Dec 21 '13 at 07:12
can you give me one example for that? – user3114045 Dec 21 '13 at 07:17
`my$str = 'aa bbb c dd eee ff mmmm rr' ; $str =~tr/abcd/1234/; print $str,"\n";` it showing `11 222 3 44 eee ff mmmm rr`.how to remove unmatched string in my output – user3114045 Dec 21 '13 at 08:22
i tried but it's not working.I'm getting same output.please tel me – user3114045 Dec 21 '13 at 09:39
` 'This pencil is .... old. You can ..... it .....';` in this how to count this dots.please let me – user3114045 Dec 21 '13 at 10:32
but how to get desire output using `tr///` – user3114045 Dec 21 '13 at 10:58
2

`tr///` doesn't accept regular expressions, and so doesn't use character classes. `tr/,[a-z]/\t[A-Z]/` works only because it is replqacing `[` with `[` and `]` with `]`. – Borodin Dec 21 '13 at 13:35
@user3114045: You shouldn't be asking additional questions in the comments. (And `mpapec`, you shouldn't be answering them!) Post anything else you have to ask as new questions. – Borodin Dec 21 '13 at 13:37

score 0 · Answer 2 · edited Aug 14 '15 at 11:06

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Use map function

@array = qw(one two three four five six seven);
@for=map{uc$_}@array;
print "@for \n";

edited Aug 14 '15 at 11:06

Kirsteins

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answered Aug 14 '15 at 09:21

Rajendra Urs

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score -1 · Answer 3 · answered Dec 21 '13 at 18:46

It's far from clear what you want. Since you have a solution, why do you want to use tr instead? Is this a homework assignment?

Because tr returns the number of characters translated, you have to join the elements of the array into a separate variable and then translate that to upper case.

This program shows a working example.

By the way, please always use strict and use warnings at the start of every program you write, especially if you are asking for help with your code.

use strict;
use warnings;

my @array = qw( one two three four five six seven );

my $arr = join ' ', @array;
$arr =~ tr/a-z/A-Z/;
print $arr, "\n";

output

ONE TWO THREE FOUR FIVE SIX SEVEN

How to print an array in upper case using tr///

3 Answers3