Convert a Char* to Std::String

convert a char* to std::string

std::string has a constructor for this:

const char *s = "Hello, World!";
std::string str(s);

Note that this construct deep copies the character list at s and s should not be nullptr, or else behavior is undefined.

How to convert char* to std::string

std::string has a constructor for this:

const char *str = "Shravan Kumar";
std::string str(str);

Just make sure that your char * isn't NULL, otherwise it will lead to undefined behavior.

std::string to char*

It won't automatically convert (thank god). You'll have to use the method c_str() to get the C string version.

std::string str = "string";
const char *cstr = str.c_str();

Note that it returns a const char *; you aren't allowed to change the C-style string returned by c_str(). If you want to process it you'll have to copy it first:

std::string str = "string";
char *cstr = new char[str.length() + 1];
strcpy(cstr, str.c_str());
// do stuff
delete [] cstr;

Or in modern C++:

std::vector<char> cstr(str.c_str(), str.c_str() + str.size() + 1);

conversion between char* and std::string and const char*

std::string A = "hello"; //< assignment from char* to string
const char* const B = A.c_str(); //< call c_str() method to access the C string
std::string C = B; //< assignment works just fine (with allocation though!)

printf("%s", C.c_str()); //< pass to printf via %s & c_str() method

C++ conversion from unsigned char to std::string

To append a character you have to use the following overloaded method append

basic_string& append(size_type n, charT c);

For example

stroutput.append(1, characters[0]);
stroutput.append(1, characters[1]);

Otherwise use method push_back or the operator +=. For example

stroutput += characters[0];
stroutput += characters[1];

If you want to append the whole array or its part then you can write

stroutput.append( reinterpret_cast<char *>( characters ), sizeof( characters ) );

stroutput.append( reinterpret_cast<char *>( characters ), n );

where n is the number of characters of the array to append.

Converting const char to std::string for title

Make your argument std::string. std::string has a constructor that takes a const char* so it should not be a problem.

Converting a const char * to std::string

std::stringhas a constructor fromconst char *.This means that it is legal to write:

const char* str="hello";
std::string s = str;

Preferred conversion from char (not char*) to std::string

std::string has a constructor that takes a number and a character. The character will repeat for the given number of times. Thus, you should use:

std::string str(1, ch);

Convert char* to string C++

std::string str(buffer, buffer + length);

Or, if the string already exists:

str.assign(buffer, buffer + length);

Edit: I'm still not completely sure I understand the question. But if it's something like what JoshG is suggesting, that you want up to length characters, or until a null terminator, whichever comes first, then you can use this:

std::string str(buffer, std::find(buffer, buffer + length, '\0'));

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