How to append a char to a std::string?

Question

int main()
{
  char d = 'd';
  std::string y("Hello worl");
  y.append(d); // this fails
  std::cout << y;
  return 0;
}

I also tried, but also failed.

int main()
{
  char d[1] = { 'd' };
  std::string y("Hello worl");
  y.append(d);
  std::cout << y;
  return 0;
}

Sorry for this dumb question, but I've searched around google, what I could see are just "char array to char ptr", "char ptr to char array", etc.

Any kind of help would be appreciated!

Thanks.

Answer 1

Use push_back():

std::string y("Hello worl");
y.push_back('d')
std::cout << y;

Answer 2

y += d;

I would use += operator instead of named functions.

Answer 3

Try the += operator link text, append() method link text, or push_back() method link text

The links in this post also contain examples of how to use the respective APIs.

Answer 4

In addition to the others mentioned, one of the string constructors take a char and the number of repetitions for that char. So you can use that to append a single char.

std::string s = "hell";
s += std::string(1, 'o');

Answer 5

If you are using the push_back there is no call for the string constructor. Otherwise it will create a string object via casting, then it will add the character in this string to the other string. Too much trouble for a tiny character ;)

Answer 6

To add a char to a std::string var using the append method, you need to use this overload:

std::string::append(size_type _Count, char _Ch)

Edit : Your're right I misunderstood the size_type parameter, displayed in the context help. This is the number of chars to add. So the correct call is

s.append(1, d);

not

s.append(sizeof(char), d);

Or the simpliest way :

s += d;

Answer 7

You don't need to search the web for good STL documentation.

One of the best sites is here: http://www.sgi.com/tech/stl/basic%5Fstring.html

Initially written by the crater of the STL.