Answer Posted / ritesh pal
A class that is used to traverse through the objects maintained by a container class. There are five categories of iterators:
input iterators,
output iterators,
forward iterators,
bidirectional iterators,
random access.
An iterator is an entity that gives access to the contents of a container object without violating encapsulation constraints. Access to the contents is granted on a one-at-a-time basis in order. The order can be storage order (as in lists and queues) or some arbitrary order (as in array indices) or according to some ordering relation (as in an ordered binary tree). The iterator is a construct, which provides an interface that, when called, yields either the next element in the container, or some value denoting the fact that there are no more elements to examine. Iterators hide the details of access to and update of the elements of a container class.
The simplest and safest iterators are those that permit read-only access to the contents of a container class. The following code fragment shows how an iterator might appear in code:
cont_iter:=new cont_iterator();
x:=cont_iter.next();
while x/=none do
...
s(x);
...
x:=cont_iter.next();
end;
In this example, cont_iter is the name of the iterator. It is created on the first line by instantiation of cont_iterator class, an iterator class defined to iterate over some container class, cont. Succesive elements from the container are carried to x. The loop terminates when x is bound to some empty value. (Here, none)In the middle of the loop, there is s(x) an operation on x, the current element from the container. The next element of the container is obtained at the bottom of the loop.
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
What do you mean by inheritance in c++?
What is data types c++?
What is the purpose of extern storage specifier?
Why do we use setw in c++?
Describe linked list using C++ with an example.
What is class invariant in c++?
Define 'std'.
What are the vectors in c++?
Explain the difference between abstract class and interface in c++?
What is meant by entry controlled loop? What all C++ loops are exit controlled?
Explain selection sorting?
What are features of c++?
Difference between a homogeneous and a heterogeneous container
What is difference between rand () and srand ()?
What is abstract keyword in c++?