Replacing Occurrences of String?

(Ajay deleted this so I (MF) am restoring it)

How do I replace every instance of 'str1' in a input sentence? My function (ReplaceStrAll) should return the intact input sentence as its output, if it cannot find any occurrence of str1 in the input sentence.

This is the code I wrote:

function output_sentence = ReplaceStrAll(input_sentence, str1, str2) 
str1_index = strfind(input_sentence,str1); 
output_sentence = [input_sentence(1:str1_index(1)-1),str2,... input_sentence( str1_index(1)+length(str1):length(input_sentence) )];

what is wrong with it? I already got verification that I'm on the right path and I just need to make a few adjustments, but what am I messing up in the code?

[Walter Roberson]

What problem are you observing with the code?

[Walter Roberson]

Content of the question was edited out of existence by the original poster :(

[Matt Fig]

Saved from google cache:

How do I replace every instance of 'str1' in a input sentence? My function (ReplaceStrAll) should return the intact input sentence as its output, if it cannot fi nd any occurrence of str1 in the input sentence.

This is the code I wrote:

function output_sentence = ReplaceStrAll(input_sentence, str1, str2) str1_index = strfind(input_sentence,str1); output_sentence = [input_sentence(1:str1_index(1)-1),str2,... input_sentence( str1_index(1)+length(str1):length(input_sentence) )];

what is wrong with it? I already got verification that I'm on the right path and I just need to make a few adjustments, but what am I messing up in the code?

Answer 1

[Andrei Bobrov]

please try this is code:

out = input_sentence;
ii = strfind(out,str1)
if ~isempty(ii)
    for ii = ii
        out = [out(1:ii-1),str2,out(ii+numel(str1):end)];
    end
end

or

out = input_sentence;
[i1,i2] = regexp(out,str1);
if ~isempty(i1)
    for ii = 1:numel(i1)
        out = [out(1:i1(ii)-1),str2,out(i2(ii)+1:end)];
    end
end

or

out = regexprep(input_sentence,str1,str2);

or

out = strrep(input_sentence,str1,str2);

[Ajay]

thanks you figured it out with the regexprep!