C + + Primer Learning Note Chapter 9

9.1 Sequential Container Sequential Containers

Vector: Fast random access,

List: Quick Insert/delete,

Deque: Double-ended queue

9.2 Scope of iterators and iterators

Iterator Operation:

*iter: Returns a reference to the element that ITER points to.

Iter->mem: The dereference of ITER is equivalent to (*iter). Mem.

++iter and iter++: Add 1 to ITER to point to the next element.

--iter and iter--: points to the next element.

Iter1 = = Iter2 and Iter1! = Iter2: Two iterators are the same element of the same container, or both point to the container when it exceeds the end of the next position when equal.

To calculate the center position of a vector object:

Vector<int>::iterator iter = Vec.begin () + vec.size ()/2;

The list container does not support arithmetic operations of iterators

Exercises Section 9.2

Exercise 9.7: The following code compiles an error, and the list's iterator does not support relational operator operations

list<int> lst1;list<int>::iterator iter1 == lst1.end ();  while (Iter1 < iter2) {  break;}

Exercise 9.8: Execute if Inner statement when iterator string is empty

　　Exercise 9.8:write a loop to Write the elements of a list reverse order.

#include <iostream>
#include <list>
#include <vector>
#include <sstream>

using namespace Std;

void Exercize_9_9 ();

int main () {
Exercize_9_9 ();
return 0;
}

void Exercize_9_9 () {
List<string> List1;
for (short i = 0; i < ++i) {
StringStream SS;
SS << I;
List1.push_back ("string" + ss.str ());
}

List<string>::iterator it = List1.end ();
Do
{
--it;
string s = *it;
cout << s.c_str () << Endl;
}
while (It! = List1.begin ());
}

Exercise 9.10:which, if any, of the following iterator uses is in error?

Constvector<int> Ivec (Ten); Vector<string> Svec (Ten); list<int> IList (Ten);(a) vector<int>::iterator it =Ivec.begin ();//Error: The iterator in Ivec is const, changed toVector<int>::const_iterator
(b) List<int>::iterator it = ilist.begin () +2;//Error: An iterator in list cannot perform arithmetic plus minus operations
(c) Vector<string>::iterator it = &svec[0]; Error: Svec[0], is a character string.
(d) for(vector<string>:: Iterator it= Svec.begin (); It! =0; ++IT)//error, it! = 0 change to it! = Svec.end ()
//....

C + + Primer Learning Note Chapter 9