vector<string> str1(3); //str1 has 3 elements
string str2 = "hello";
char str3[] = "HELLO";
str1[0]= "Hello";
cout<<"The size of vector str1 is "<<sizeof(str1)<<endl; //the size of vector str1
cout<<"The size of string str2 is "<<sizeof(str2)<<endl; //the size of string str2
cout<<"The size of char str3, including the ending \'\\0\' is "<<sizeof(str3)<<endl; //the size of char[] str3, including the ending '\0'
cout<<"The elements of vector str1 is "<<str1.size()<<endl; //the elements of vector str1;
cout<<"The lenght of string str2 is "<<str2.size()<<endl; //the length of string str2;
cout<<"The length of string str2 is "<<str2.length()<<endl; //the length of string str2;
cout<<"The length of char[] str3, excluding the ending \'\\0\' is "<<strlen(str3)<<endl; //the length of char[] str3, excludes the '\0'