Double letters?

[dfhtextpipe]

Hi Simon,

Is there an easy method to search for double letters?

David

[DataMystic Support]

Yes David,

Just use a perl pattern of

Code: Select all

([a-z])\1

[dfhtextpipe]

Did you understand my question?

I want a simple method to find double letters, not just two letters that may or may not be the same.

(aa|bb|cc|dd ... |xx|yy|zz) would do it, but there must be a shorter pattern, surely.

David

[DataMystic Support]

Hi David,

[a-z]{2} will find two letters, what I wrote first does in fact work!

[dfhtextpipe]

How amazing!

I'm still struggling to understand how it does work.

Code: Select all

000084	aa
000018	ee
000406	ii
000021	oo
000009	ss
000009	uu
000223	vv

David

[DataMystic Support]

\1, \2 etc in perl parlance refer to the previously matched text in captured sub-pattern 1, 2 etc.