Matching strings without repeated spaces

[usenet]

I want to construct a regexp which will match a string containing only
\w and \s, but not repeated whitespaces. I can do it (crudely) with
two regexps, such as:

if (/[\w\s-]+$/ && ! /\s\s/) {

but I'd rather do it with a single regexp... but guessing at the syntax
has not proved effective.

I'd appreciate some insight...

Thanks!

 

[Tad McClellan]

I want to construct a regexp which will match a string containing only
\w and \s,

Then you should anchor _both_ ends of the pattern.

but not repeated whitespaces. I can do it (crudely) with
two regexps, such as:

if (/[\w\s-]+$/ && ! /\s\s/) {

but I'd rather do it with a single regexp...

I'd appreciate some insight...

Use a negative lookahead assertion:

if ( /^(\w+|\s(?!\s))+$/ ) {

or, written for human consumption:

if ( /^ (
\w+
|
\s(?!\s)
)+
$/x
) {

 

[Xicheng Jia]

I want to construct a regexp which will match a string containing only
\w and \s, but not repeated whitespaces. I can do it (crudely) with
two regexps, such as:

if (/[\w\s-]+$/ && ! /\s\s/) {

but I'd rather do it with a single regexp... but guessing at the syntax
has not proved effective.

I'd appreciate some insight...

Thanks!

how about this

if (/^(?:\w\s?)*$/) { ... }

Xicheng