Perl : Changing a single char in a string

richhill · 09-17-2003, 04:02 PM

I want to change a single character in a string

Example:

$mystring = "..........";

$n = argv[1];

#How do I change $mystring so that the nth character
# is now ^ ?

print $mystring; # ...^.......

I'm not inserting a char - I'm replacing.

Thanks

richhill · 09-17-2003, 04:22 PM

Well I guess I may have found the answer myself.

substr($mystring, $n, 1) = "^"

will do the trick.

Correct me if I'm wrong.

allo · 09-17-2003, 04:31 PM

Hello,

A heavy way with regular expression :

$n =~ s/^(.{5})./$1\^/;

Here I suppose for example you want to change the 6th character in string - The reason for the 5 : 6 -1 between {}. The first "^" means the the beginning of the string and the second with the backslash before means the character "^" and not the beginning of the string like the first one.