Re: howto replace part of a string

So, using substr as an lvalue worked (so my problem is solved :)
But I still don't understand why the following example doesn't work:

$a = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' ;
($a = $a ) =~ s/^\S{5}(\S{4})\S+/\1xxxx/ ;
[download]

any suggestions ?

LuCa

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Re^2: howto replace part of a string by Tanktalus (Canon) on Jun 14, 2006 at 15:28 UTC
Well, for starters, you're using 5, 4, and , rather than 10 and 20. Secondly, you're ignoring the warning message: `\1 better written as $1 at ./z.pl line 7.` [download] (You are* using strict and warnings, right?) Third - what's with the `($a = $a )`? Finally, you've inverted the problem. You're replacing everything except characters 6 through 9. You probably want something like: `$a =~ s/^(\S{5})\S{4}/$1xxxx/;` [download] Or, potentially simpler: `$a =~ s/(?<=^\S{5})\S{4}/xxxx/;` [download] But what you really want is still substr.	[reply] [d/l] [select]
Re^3: howto replace part of a string by jeanluca (Deacon) on Jun 14, 2006 at 16:08 UTC
So, now I understand what I was doing (or not doing). I never understood the \1, and I don't know why I do ( $a = $a ) too, I think I once copied it from somewhere without understanding it Thanks a lot Luca	[reply]
Re^2: howto replace part of a string by CountOrlok (Friar) on Jun 14, 2006 at 15:26 UTC
Is this what you're trying to do? `$a = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'; $a =~ s/^\S{5}(\S{4})\S+/$1xxxx/ ;` [download] -imran	[reply] [d/l]
Re^3: howto replace part of a string by jeanluca (Deacon) on Jun 14, 2006 at 16:04 UTC
You're right, but I realize now, because I didn't understand the expression, that it is not what I want!	[reply]