Using a loop to replace spaces for underscore

Hello there, I am a complete begginer in Matlab and was given an exercise that took me a whole day and still, no success.

The following function puts a '\' in front of every underscore. I have to change this function in a way that it replaces every space for an underscore.

locs = strfind(instring, '_'); % finding all underscores

if isempty(locs)

outstring = instring;

else

outstring_start_ind = 1;

instring_start_ind = 1;

for underscore_cnt = 1:length(locs) % for each underscores

outstring(outstring_start_ind:(locs(underscore_cnt)+underscore_cnt-2)) = ...

instring(instring_start_ind:(locs(underscore_cnt)-1));

outstring(locs(underscore_cnt)+underscore_cnt-1) = '\';

outstring_start_ind = locs(underscore_cnt)+underscore_cnt;

instring_start_ind = locs(underscore_cnt);

end

outstring(outstring_start_ind:(length(instring)+underscore_cnt)) = ...

instring(instring_start_ind:end);

end

Is there someone who can give me a hand here, please? Thank you.

[Jonas]

do you have to use the basic structure of the given function? if not, just use the strrep() function which replaces a specific character array by another

[Laura Mendes]

ok, thank you very much. could you show me how would I use it ?

[Jonas]

if you want to replace every space with an underscore you could call

strOut=strrep(strIn,' ','_');

[Laura Mendes]

Ok, thank you. But actually I should use the basic structure of the function I posted. Do you have ideas? Thank you

[Laura Mendes]

I tried this function within the main code where I use the posted function, and it did not work... :/

[Laura Mendes]

I did it thank u very much

Answer 1

[John D'Errico]

Ye gods, that is a complicated way to solve a job poorly. Sorry, but it is. Two lines, assuming you want the result in outstring. One line, if you are willing to replace in the original string.

outstring = instring;
outstring(instring == '_') = ' ';

That replaces every underscore with a space.

[Laura Mendes]

I had to change something here, but it HELPED! Thank you so much for the support!

Answer 2

[Steven Lord]

Use the replace function.

before = 'Hello world'

before = 'Hello world'

after = replace(before, ' ', ' cruel ')

after = 'Hello cruel world'

[Laura Mendes]

Thank you :)