How to convert a string literal to unsigned char array in visual c++

Question

How to convert a string to Unsigned char in c++...

I have,

unsigned char m_Test[8];

I want to assign a string \"Hello world\"

Answer 1

You can use strcpy:

unsigned char m_Test[8];
strcpy((char*)m_Test, "Hello world");

Note that "Hello world" is too long for 8 bytes, so you will probably get a segfault.

Answer 2

Firstly, the array has to be at least big enough to hold the string:

 unsigned char m_Test[20];

then you use strcpy. You need to cast the first parameter to avoid a warning:

 strcpy( (char*) m_Test, "Hello World" );

Or if you want to be a C++ purist:

 strcpy( static_cast <char*>( m_Test ), "Hello World" );

If you want to initialise the string rather than assign it, you could also say:

 unsigned char m_Test[20] = "Hello World";

Answer 3

You can use a string copy function like strcpy or even better strncpy, which has also some size checks:

strncpy ((char*) m_Test,"Hello World",8);

Answer 4

You can use c_str() function of std::string to get the char* out of string. This method basically returns a pointer to c-style string. After this you can use the normal string copying functions such as strcpy or strncpy to copy the value in to test.

Answer 5

you can use strcpy function But have in mind that m_Test is only 8 size and there will be an overflow. Strcpy won't check that and you will get an exception

char * strcpy ( char * destination, const char * source );

Answer 6

strncpy(m_Test, "Hello world", sizeof(m_Test));

Here's Wikipedia on strncpy: