如何用Perl中的步骤生成范围？

Question

在bash,seq 5 5 20生产5 10 15 20.

在Perl中,1..5生产1 2 3 4 5; 它支持步骤吗？

如何用Perl中的步骤生成范围？

Answer 1

perldoc -f map是一种方式:

use warnings;
use strict;
use Data::Dumper;

my @ns = map { 5 * $_ } 1 .. 4;
print Dumper(\@ns);

__END__

$VAR1 = [
          5,
          10,
          15,
          20
        ];

另见:perldoc perlop

Answer 2

Perl中的范围运算符不支持步骤.您可以使用for循环代替:

for (my $i = 5; $i <= 20; $i += 5) {
    print "$i\n";
}

Answer 3

该功能执行此操作:List::Gen range

use strict;
use warnings;
use feature 'say';
use List::Gen;

my $range = range 5, 20, 5;

say for @$range;      # 5
                      # 10
                      # 15
                      # 20

say while <$range>;   # TIMT1WTDI
$range->say;          # TAMT2WTDI, v.0.974
say $range->str;      # TAMT3WTDI, v.0.974

my $by_fives = <5 .. 20 by 5>;

say while <$by_fives>;     #TAMT4WTDI
<5 .. * by 5>->say( 4 );   #TAMT5WTDI

Answer 4

不如工具

use warnings;
use strict;

my @ns;

for my $n (1..4) {
    push(@ns, $n*5);
}