How can I split a string and assign new values to the strings?

If if want to change the string

str='Hello'

Into a new string with the values

str='Hotel-Echo-Lima-Lima-Oscar'

How do I do that?

Answer 1

[Guillaume]

This is even simpler, using the newly introduced replace (R2016b):

natoLookup = {'h','Hotel-';
              'e','Echo-';
              'l','Lima-';
              'o','Oscar-';
              };
replace(lower('Hello'), natoLookup(:, 1), natoLookup(:, 2))

[the cyclist]

Oooh, nice!

Please unaccept my answer and accept this one!

Answer 2

[the cyclist]

Here is one way:

natoLookup = {'h','Hotel-';
              'e','Echo-';
              'l','Lima-';
              'o','Oscar-';
              };

str = 'Hello';

newstr = '';

for nc = 1:numel(str)
    [tf,loc] = ismember(lower(str(nc)),natoLookup(:,1));
    newstr = [newstr,natoLookup{loc,2}];
end

% Trim the excess hyphen
newstr(end) = [];

[JVM]

Does this work in generel? Or is it just in this case with 'Hello'?

[Image Analyst]

If you modify natoLookup to include every character you want to replace (the whole alphabet plus symbols) and change str to be whatever word you want to operate on, then it will be completely general.

[the cyclist]

As @ImageAnalyst states, it will be general after you generalize the lookup table.

One other quick comment: If you are planning to use this with very long text, it would be best to modify this code to preallocate memory for newstr. The current algorithm will manage memory poorly.

Answer 3

[Stephen23]

Using indexing means no loops and a very memory-efficient method:

>> str = 'Hello World!';
>> tmp = num2cell(str);
>> idx = isletter(str);
>> C = {'Alpha', 'Bravo', 'Charlie', 'Delta', 'Echo', 'Foxtrot', 'Golf', 'Hotel', 'India', 'Juliet', 'Kilo', 'Lima', 'Mike', 'November', 'Oscar', 'Papa', 'Quebec', 'Romeo', 'Sierra', 'Tango', 'Uniform', 'Victor', 'Whiskey', 'Xray', 'Yankee', 'Zulu'};
>> tmp(idx) = strcat(C(1+upper(str(idx))-'A'),'-');
>> [tmp{:}]
ans = Hotel-Echo-Lima-Lima-Oscar- Whiskey-Oscar-Romeo-Lima-Delta-!

Or with a bit of attention to the hyphens:

>> D = {'','-'};
>> idy = idx & [idx(2:end),false];
>> tmp(idx) = strcat(C(1+upper(str(idx))-'A'),D(1+idy(idx)));
>> [tmp{:}]
ans = Hotel-Echo-Lima-Lima-Oscar Whiskey-Oscar-Romeo-Lima-Delta!