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

Question

The following fails with the error prog.cpp:5:13: error: invalid conversion from ‘char’ to ‘const char*’

int main()
{
  char d = \'d\';
  std::s         


        

Answer 1

int main()
{
  char d = 'd';
  std::string y("Hello worl");

  y += d;
  y.push_back(d);
  y.append(1, d); //appending the character 1 time
  y.insert(y.end(), 1, d); //appending the character 1 time
  y.resize(y.size()+1, d); //appending the character 1 time
  y += std::string(1, d); //appending the character 1 time
}

Note that in all of these examples you could have used a character literal directly: y += 'd';.

Your second example almost would have worked, for unrelated reasons. char d[1] = { 'd'}; didn't work, but char d[2] = { 'd'}; (note the array is size two) would have been worked roughly the same as const char* d = "d";, and a string literal can be appended: y.append(d);.