string

[Sharan123]

Can someone explain the output line by line code for example what is append what is string::iterator

 string str = "Nobody is perfect";
string s = ""; // empty string
char *ch = "abcdef";
s.append(str,0,6);
cout << "s is : " << s << endl;
string::iterator inpIt1 = str.begin()+6;
string::iterator inpIt2 = str.end();
s.append(inpIt1,inpIt2);
cout << "s is : " << s << endl;
s.append(3,'!');
cout << "s is : " << s << endl;
s.append(ch,3);
cout << "s is : " << s << endl;
s.append(ch,3);
cout << "s is : " << s << endl;

[coder777]

Read this:

http://www.cplusplus.com/reference/string/string/

append is what it implies: it adds some characters to the string.

string::iterator is basically a pointer to a character in the string.

[Sharan123]

Just one thing why cant we write string inIt1=str.begin()+6;
in line 6

[Dy7SLyTq]

you can do that. no one said you couldnt. its called pointer arithmatetic

[Sharan123]

But if we can do that why use iterator

[Dy7SLyTq]

an iterator is just a pointer to a string. and you are'nt being clear. why based on the fact that you can do str.begin()+6 should you not have to use iterators?

[Sharan123]

The thing i am confused about if iterator is just a pointer than wouldn't it be correct just to have string *inpIt1=str.begin()+6;
is iterator just used to have genracity in program ?

[coder777]

than wouldn't it be correct just to have string *inpIt1=str.begin()+6;

No, it is not a pointer to string. It's a pointer to internal data. So it'd rather be char *.
On the other side: it's an iterator. All you need to know is that it obeys some according rules.

[Dy7SLyTq]

No, it is not a pointer to string.

i apologize... my mistake. i havent built a container in a while. yeah its not actually a pointer to a string. its a pointer to what the class basic_string<char> contains.

[Sharan123]

THank you :)