in reply to How to use Substr to bulk substitutions?

In general, using Perl regex is much better than running substr() multiple times on a single expression.
Where are you using substr()?
My version of Perl does not allow:
my $capture1 = $string, 6, 2, "is stretched"; 
#!/usr/bin/perl
use strict;
use warnings;

my $string = 'This is string';
my $capture1 = $string, 6, 2, "is stretched"; # This will substitute a
+s expected
my $capture2 = $string, 9, 6, 'STRING'; # Now here original string wil
+l be updated and positions I have already are of no use.

__END__
Useless use of a constant (6) in void context at C:\test.pl line 6.
Useless use of a constant (2) in void context at C:\test.pl line 6.
Useless use of a constant ("is stretched") in void context at C:\test.
+pl line 6.
Useless use of a constant (9) in void context at C:\test.pl line 7.
Useless use of a constant (6) in void context at C:test.pl line 7.
Useless use of a constant ("STRING") in void context at C:\test.pl lin
+e 7.

Process completed successfully

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Re^2: How to use Substr to bulk substitutions?
by phoenix007 (Sexton) on May 17, 2019 at 04:42 UTC

    That was typo now I have corrected it

[reply]
      Updated code:
      #!/usr/bin/perl
use strict;
use warnings;

my $string = 'This is string';
my $capture1 = substr $string, 6, 2, "is stretched"; # This will subst
+itute as expected

# REALLY?

print $string,"\n";

#  I get:
#  "This iis stretchedstring"

# perhaps better is:
my $string2 = 'This is string';
$string2 =~ s/string/streched string/;
print "$string2\n";

#  that prints:
#  "This is streched string"

# Your second substr():

substr $string, 9, 6, 'STRING';
print $string,"\n";

# that prints:
# This iis STRINGhedstring

# I suspect that you want:
$string2 =~ s/string/STRING/;
print "$string2\n";

# that prints:
# "This is streched STRING"

      [download]
      Perl is wonderful with what are called "regular expressions" or regex'es. In general, use the power of the Perl language. substr() is a low level thing that can be used, but is very, very rare in Perl programs. substr() is very common in C programs because there is not a "built in regex" operator.

      To summarize: 

      #!/usr/bin/perl
use strict;
use warnings;

my $string = "This is string";
print "$string\n";

$string =~ s/string/stretched string/;
$string =~ s/string/STRING/;

print "$string\n"; 

__END__
This is string
This is stretched STRING

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