Is there any difference between (\w+)? and (\w*) in regex?
It seems the same, doesn’t it?
Is there any difference between (\w+)? and (\w*) in regex? It seems the same,
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Is there any difference between (\w+)? and (\w*) in regex?
It seems the same, doesn’t it?
(\w+)?and(\w*)both match the same (0..+inf word characters)However, there is a slight difference:
In the first case, if this part of the regex matches
"", the capturing group is absent. In the second case, it is empty. In some languages, the former manifests as anullwhile the latter should always be"".In Javascript, for example,
In PHP (
preg_match), in the former case, the corresponding key is simply absent in the matches array: http://3v4l.org/DB6p3#v430