Get Number of regex matches

Ruby
1

Hi,

how can I get the NUMBER of matches for a regular expression in a given
string?

For example: for string ‘Banana’ and regex /a/ I should get ‘3’
(matches)

Thanks!
Ingo

2

On 12/7/06, Ingo W. [email protected] wrote:

Hi,

how can I get the NUMBER of matches for a regular expression in a given
string?

For example: for string ‘Banana’ and regex /a/ I should get ‘3’
(matches)

Here’s one way (but there are probably better ones):

“Banana”.scan(/a/).size
=> 3

max

3

On 12/6/06, Ingo W. [email protected] wrote:

Hi,

how can I get the NUMBER of matches for a regular expression in a given
string?

For example: for string ‘Banana’ and regex /a/ I should get ‘3’
(matches)

One way is:
‘Banana’.scan(/a/).size

I’m not sure how to get it out of the MatchData returned by ‘match’ or
=~, unfortunately.

4

On 12/7/06, Max M. [email protected] wrote:

Here’s one way (but there are probably better ones):

“Banana”.scan(/a/).size
=> 3

This one skips the intermediate array construction in return for some
clunkiness:

i = 0
banana.scan(/a/) { i += 1}
i

martin

5

On 06.12.2006 22:44, Martin DeMello wrote:

i

require ‘enumerator’
=> true

“banana”.to_enum(:scan, /a/).inject(0) {|s,| s+1}
=> 3

:slight_smile:

robert
6

Thank you very much for all your great suggestions!

Ingo

7

On 2006-12-07 04:02:55 -0500, Robert K. [email protected]
said:

banana.scan(/a/) { i += 1}
i

require ‘enumerator’
=> true
“banana”.to_enum(:scan, /a/).inject(0) {|s,| s+1}
=> 3

:slight_smile:

robert

banana.split(‘’).reject { |i| i if i != ‘a’ }.length

I want extra points for using “banana.split”.

Best,
James