replacing text in a string using indexing

4 views (last 30 days)
Lin
Lin on 21 Sep 2022
Edited: Stephen23 on 21 Sep 2022
how could replace text by just using one line of code
e.g. a = 'qqqqqq' and I want to make q = 'qweqwe'

Answers (2)

Mathieu NOE
Mathieu NOE on 21 Sep 2022
I win the prize !
out = strrep('qqqqqq','qqqqq','qwe')
out =
'qweqwe'
  2 Comments
Mathieu NOE
Mathieu NOE on 21 Sep 2022
look at the doc for function strrep
strrep Find and replace substring.
MODIFIEDTEXT = strrep(ORIGTEXT,OLDSUBTEXT,NEWSUBTEXT) replaces all
occurrences of the text OLDSUBTEXT within text ORIGTEXT with the
text NEWSUBTEXT.
the trick here is to count how many times you want the pattern 'qwe' repeated in the output (modified) text
you last query request 3 time 'qwe' to make 'qweqweqweq' so we will take the input text ('qqqqqqqqqq') and remove 3 - 1 = 2 'q' from this character to create the subtext
here a liitle demo where I remove 0,1,2 times the q
out1 = strrep('qqqqqqqqqq' ,'qqqqqqqqqq' ,'qwe') % zero 'q' removed in subtext (compared to input text)
out2 = strrep('qqqqqqqqqq' ,'qqqqqqqqq' ,'qwe') % one 'q' removed in subtext
out3 = strrep('qqqqqqqqqq' ,'qqqqqqqq' ,'qwe') % two 'q' removed in subtext
out1 = 'qwe'
out2 = 'qweqwe'
out3 = 'qweqweqwe'

Sign in to comment.


Stephen23
Stephen23 on 21 Sep 2022
Edited: Stephen23 on 21 Sep 2022
For overlapping matches use STRREP.
For non-overlapping matches use REGEXPREP:
regexprep('qqqqqq','qqq','qwe')
ans = 'qweqwe'
regexprep('qqqqqqqqq','qqq','qwe')
ans = 'qweqweqwe'

Categories

Find more on Characters and Strings in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!