Dynamic regular expression replacement: token number

Hi,

I was trying to do something that sounded simple... but I'm stuck!

Trying to replace matched tokens using regexprep, but I'd like to replace them with there token number dynamically.

For example:

regexprep('(first matched_token)_fjezhfjksdhf_(second matched_token)','matched_token', 'matchednumber_$DUNNO?')

would output

(first matchednumber_1)_fjezhfjksdhf_(second matchednumber_2)

Any idea appreciated, thanks!

Answer 1

[Sai Veeramachaneni]

You can use something similar to below code to simulate the required behavior.

str='(first matched_token)_fjezhfjksdhf_(second matched_token)';
i=0;
while true
    i=i+1;
  temp=regexprep(str,'matched_token',strcat("matchednumber_",num2str(i)),'once');
    if isequal(temp,str)
        break
    end
    str=temp;
end
str

Answer 2

[Stephen23]

It can be done with one dynamic replacement expression:

>> str = '(1st MT)_fjezhfjksdhf_(2nd MT)';
>> rgx = 'MT';
>> out = regexprep(str, rgx, 'MN_${num2str(1+numel(regexp($`,rgx)))}')
out =
(1st MN_1)_fjezhfjksdhf_(2nd MN_2)

See:

https://www.mathworks.com/help/matlab/matlab_prog/dynamic-regular-expressions.html