C++ string initialization
string s0; // s0 = “”
string s1(“Hello”); // s1 = “Hello”
string s2 (s1); // s2 = “Hello”
string s3 (s1, 1, 2); // s3 = “el”
string s4 ("Hello World", 5); // s4 = “Hello”
string s5 (5, ‘*’); // s5 = “*****”
string s6 (s1.begin(), s1.begin()+3); // s6 = “Hel”