regex - Substitution with \s does not work as expected -

i write regex remove more 1 space in string. code simple:

my $string = 'a string has more 1      space'; $string = s/\s+/\s/g; 

but, result bad: 'asstringshassmoresthans1sspace'. replaces every single space 's' character.

there's work around instead of using \s substitution, use ' '. regex becomes:

$string = s/\s+/ /g; 

why doesn't regex \s work?

\s metacharacter in regular expression (and matches more space, example tabs, linebreak , form feed characters), not in replacement string. use simple space (as did) if want replace whitespace single space:

$string = s/\s+/ /g; 

if want affect actual space characters, use

$string = s/ {2,}/ /g; 

(no need replace single spaces themselves).