A question on regexprep

1 ビュー (過去 30 日間)
Edward Huang
Edward Huang 2019 年 8 月 19 日
コメント済み: Edward Huang 2019 年 8 月 19 日
This is a question stem from a Cody Problem when I looked through those efficient solutions. Let's say I have the following code:
s = 'John got an A in math.';
regexprep(s,'\<(\w)(\w*)(\w)\>','$1${$2(end:-1:1)}$3');
If I try to replace each match with only one of its tokens:
regexprep(s,'\<(\w)(\w*)(\w)\>','$1'); % or '$2','$3'
I will find that 'A' can be recognized as any one of them, and yet when it is replaced by '$1${$2(end:-1:1)}$3', only one copy of 'A' is returned. Why?
Thank you in advance.

採用された回答

TADA
TADA 2019 年 8 月 19 日
A is not a match for your regexp,
match = regexp(s,'\<(\w)(\w*)(\w)\>', 'match')
match =
1×5 cell array
{'John'} {'got'} {'an'} {'in'} {'math'}
so it's not replaced by anything,
  1. 'John' was replaced by 'ho'
  2. 'got' was replaced by 'o'
  3. 'an' was replaced by ''
  4. A is not a match, not replaced
  5. 'in' was replaced by ''
  6. 'math' was replaced by 'ta'
s2 = regexprep(s,'\<(\w)(\w*)(\w)\>','${$2(end:-1:1)}')
s2 =
'ho o A ta.'
  1 件のコメント
Edward Huang
Edward Huang 2019 年 8 月 19 日
Oops... I didn't realize I could have checked with regexp... Thanks!

サインインしてコメントする。

その他の回答 (0 件)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by