#include <bits/stdc++.h>
using namespace std;
int main()
{
string s1 = "Alice";
s1 +='\0';
s1 +='\0';
cout << s1.size() << endl; // output: 7
string s2 = "Alice";
s2 += "\0";
s2 += "\0";
cout << s2.size() << endl; // output: 5
}
What is wrong here?
Please explain the difference between role of single quotes and double quotes in concatenation.
s1 +='\0';
adds the character to s1 regardless of what the character is.
s2 += "\0";
adds a null terminated string to s2. Because of that, the embedded null character of the RHS is seen as a string terminator for the purposes of that function. In essence, that is equivalent to
s2 += "";
That explains the difference in output that you observed.
You can use std::string::append to append embedded null characters of a char const* object.
s2.append("\0", 1);
\0 character is the only way to know if the string ended!
s2 += "\0"; and s1 +='\0';, do you? '\0' is not a string literal.
s2 += "\0"; twice increased the string length by one. That was edited out (not by OP), assumed to be a typo. Vlad probably assumes it's not.
s2.std::string? I can't repro on libstdc++, libc++, and MSVC's library.