Simple question (in C++):
How do I convert a single character into a string. So for example, I have string str = "abc";
And I want to extract the first letter, but I want it to be a string as opposed to a character.
I tried
string firstLetter = str[0] + ""; and
string firstLetter = & str[0]; Neither works. Ideas?
Off the top of my head, if you're using STL then do this:
string firstLetter(1,str[0]); 
std::string is not from that part of the standard library that was derived from the STL.
string named firstLetter that grabs 1 character starting from str's first ([0]) element." en.cppreference.com/w/cpp/string/basic_string/basic_string
str, because str isn't even passed, rather the character at str[0] is passed by value. If you use 2 instead of 1 you'll get two copies of the first character, not the first two characters. That's directly from your link where you can see it's form (2) of the constructor, documented as: 2) Constructs the string with count copies of character ch. The behavior is undefined if count >= npos.You can use the std::string(size_t , char ) constructor:
string firstletter( 1, str[0]); or you could use string::substr():
string firstletter2( str.substr(0, 1)); 1) Using std::stringstream
std::string str="abc",r; std::stringstream s; s<<str[0]; s>>r; std::cout<<r; 2) Using string ( size_t n, char c ); constructor
std::string str="abc"; string r(1, str[0]); 3) Using substr()
string r(str.substr(0, 1)); 
string r(&str[0], 1); or string r(str.c_str(), 1);string s; char a='c'; s+=a; //now s is "c" or
char a='c'; string s(1, a); //now s is "c" 
std::string does not have a constructor that accepts a single char as input by itself, so string s(a); will not work. However, string s(1, a); and string s(&a, 1); will work instead.Use string::substr.
In the example below, f will be the string containing 1 characters after offset 0 in foo (in other words, the first character).
string foo = "foo"; string f = foo.substr(0, 1); cout << foo << endl; // "foo" cout << f << endl; // "f" 
char characterVariable = 'z'; string cToS(1, characterVariable); //cToS is now a string with the value of "z" string firstletter(str.begin(), str.begin() + 1);
you can try this it works
string s="hello"; string s1=""; s1=s1+s[0]; A lot of the other answers are correct, but with syntax that leaves a lot to be desired. As of C++11, you can use the initializer list constructor of std::string (overload (15) on cppreference).
With this constructor, turning the first char into a std::string named first_letter is as trivial as:
std::string first_letter{ str.front() }; If you want to return a string, there 2 ways to do this is given below:
1.`return (string) "" + S[i];
2.string s.push_back(originals[k];return s;
