Replacing Wchar_t

Question

How can I replace string in a wchar_t variable?

wchar_t text[] = L"Start Notepad.exe";

I want to replace Notepad.exe with Word.exe.

You can do this by writing the correct code do this, then compiling and executing it. — Sam Varshavchik, Mar 20 '16 at 12:41
@Galik Thanks but, Windows expects `wchar_t` for most of its functions and it is really pain to convert from `wstring` to `wchar_t`. That is why I try to use `wchar_t`. Even `wstring.c_str()` does not help because sometimes VS requires it to be not a `constant`. What do you recommend? — John Sewell, Mar 20 '16 at 12:59
If you want a non-constant `wchar_t*` then you can pass `&text[0]` like: `winfunc(&text[0], text.size());` — Galik, Mar 20 '16 at 13:05
@Galik thanks again. But would there be any issues when using `&text[0]` ? Because I am dealing with international characters for localization. Not sure if passing first pointer cause any `utf16` character loss? Is not there any standard way for dealing with `wchar_t`? — John Sewell, Mar 20 '16 at 13:11
There is no difference passing `&text[0]` and passing the address of a `wchar_t` array. In fact the `std::wstring` class is basically just a wrapper around a dynamic `wchar_t*` array. — Galik, Mar 20 '16 at 13:17
You won't even lose any performance because `std::wstring` methods are trivial, inlined and calling them is optimized away by the compiler. Its just as fast as an array (because that's what it is). — Galik, Mar 20 '16 at 13:27
see [Modifying underlying char array of a c++ string object](https://stackoverflow.com/q/5729203/995714) — phuclv, Mar 31 '19 at 10:41

score 2 · Accepted Answer · edited May 23 '17 at 12:07

2

wchar_t is just one character, not the string. In your case you need std::wstring, string consisting of wchar_t. Here is answer on how to replace one substring with another.

edited May 23 '17 at 12:07

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answered Mar 20 '16 at 12:44

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I updated my question. Sorry for the typo. wchar_t is array in my case. Am I still can not replace this way? – John Sewell Mar 20 '16 at 12:51

score 0 · Answer 2 · edited Mar 31 '19 at 21:26

Basically you need to use a pointer or index variable and replace the characters one by one and end with the null character.

Here is an example, (note that C++ programmers might hate this code, but is fairly acceptable for C programmers...):

wchar_t lpSrcText[] = L"Start Notepad.exe";
wchar_t const * lpReplace = L"Word.exe";

int i = 0;
while(*(lpReplace + i))
{
     lpSrcText[6 + i] = *(lpReplace + i);
     i++;
}
*(lpReplace + i) = L'\0';

Replacing Wchar_t

2 Answers2