added finding all matches page

[brigand]

With regular expressions you often want to find more than the first match. It's pretty easy to do in CoffeeScript.

[sukima]

The problem description leaves me wondering why regular JS doesn't have this. Why does /patter/g not work in this case?

Maybe expanding the problem text to explain that this recipe is a convenience function around manually looping through the results from /pattern/g.

[brigand]

It's one of JavaScript's shortcommings. For example, Python has a findall method.

Consider this example. We only get the first match. If we try it again, we get the same match.

s = "I have 4 dogs, 7 cats, and 42 gold fish."
/\d+/g.exec(s)
# => ["4"]
/\d+/g.exec(s)
# => ["4"]

Now, we save a reference to our expression. This lets us get all of the matches.

myRegEx = /\d+/g
myRegEx.exec s
# => ["4"]
myRegEx.exec s
# => ["7"]
myRegEx.exec s
# => ["42"]
myRegEx.exec s
# => null

By using the prototype we are sure we're always referencing the same regex, and it's a lot more succinct than saving a reference to each expression we would like to use, and less error prone. I'm not sure exactly how to explain this in the usual couple of sentences that the problem definition is.

Any ideas?

[sukima]

Yeah! makes more sense now.

[brycec]

Should be /\d+/g

[brycec]

Alternatively, you could just use String.match with a global regex, like so:

"I have 4 dogs, 7 cats, and 42 gold fish.".match /\d+/g # -> ["4", "7", "42"]

[brigand]

Huh, I forgot about that. Nevermind, this page isn't needed.