Re: How do I cut single characters out of a string

I'm surprised that nobody has mentioned that substr returns an lvalue. In other words, you can assign to it.

my $string = 'mystring123456';
substr($string, 8, 1) = '';
print "$string\n";
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Re^2: How do I cut single characters out of a string by johngg (Canon) on Jan 15, 2012 at 12:22 UTC
Way back in the early days of Perl 5 substr didn't have the facility to supply a fourth argument so assigning to it as you describe was the only way to go. The advantage of using the 4-arg form to replace text is that what has been replaced is returned. Thus you can chain `substr`s together to move text around. `knoppix@Microknoppix:~$ perl -E ' > $str = q{abcdefghijk}; > say $str; > substr $str, 5, 2, substr $str, 3, 2, substr $str, 5, 2; > say $str;' abcdefghijk abcfgdehijk knoppix@Microknoppix:~$ perl -E '` [download] Of course, that particular example can be done more simply with a regex substitution but it can be a useful technique sometimes. `knoppix@Microknoppix:~$ perl -E ' > $str = q{abcdefghijk}; > say $str; > $str =~ s{^...\K(..)(..)}{$2$1}; > say $str;' abcdefghijk abcfgdehijk knoppix@Microknoppix:~$` [download] I hope this is of interest. Cheers, JohnGG	[reply] [d/l] [select]
Re^3: How do I cut single characters out of a string by tobyink (Canon) on Jan 15, 2012 at 12:53 UTC
`substr $str, 5, 2, substr $str, 3, 2, substr $str, 5, 2;` I'll have to remember that next time I'm entering an obfuscated code contest.	[reply] [d/l]
Re^2: How do I cut single characters out of a string by JavaFan (Canon) on Jan 15, 2012 at 02:44 UTC
Noone has mentioned that, but already 2 people before you used 4-arg substr, which in this case does the same thing.	[reply]