How to split a string on comma that is NOT followed by a space?

Question

I want the results to be:

Cats, Felines & Cougars    
Dogs    
Snakes

This is the closest I can get.

$string = "Cats, Felines & Cougars,Dogs,Snakes";
$result = split(',[^ ]', $string);
print_r($result);

Which results in

Array
(
    [0] => Cats, Felines & Cougars
    [1] => ogs
    [2] => nakes
)

Answer 1

You can use a negative lookahead to achieve this:

,(?!\s)

In simple English, the above regex says match all commas only if it is not followed by a space (\s).

In PHP, you can use it with preg_split(), like so:

$string = "Cats, Felines & Cougars,Dogs,Snakes";
$result = preg_split('/,(?!\s)/', $string);
print_r($result);

Output:

Array
(
    [0] => Cats, Felines & Cougars
    [1] => Dogs
    [2] => Snakes
)

Answer 2

the split() function has been deprecated so I'm using preg_split instead.

Here's what you want:

$string = "Cats, Felines & Cougars,Dogs,Snakes";
$result = preg_split('/,(?! )/', $string);
print_r($result);

This uses ?! to signify that we want split on a comma only when not followed by the grouped sequence.

I linked the Perl documentation on the operator since preg_split uses Perl regular expressions:

http://perldoc.perl.org/perlre.html#Look-Around-Assertions