What is an Iterator class?
- 1 Answers
- 795 Views
- I also Faced
- E-Mail Answers
Answer / 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 |
Why do we use pointers in c++?
What do you mean by a template?
What is the difference between "calloc" and "malloc"?
What is the extraction operator and what does it do?
Why is c++ called oops?
Is c++ platform dependent?
How can you link a c program with a c function?
Suppose that data is an array of 1000 integers. Write a single function call that will sort the 100 elements data [222] through data [321].
can any one help to find a specific string between html tags which is changed to a sting.. weather.html looks (for location) is <location>somewhere</location> #include <iostream> #include <fstream> #include <string> using namespace std; string find_field(string myPage,string); int main (void) { string page, line, location, temperature; ifstream inputFile("weather.xml"); while(getline(inputFile, line)) { page.append(line); line.erase(); } // Now page is a string that contains the whole xml page // Here you need to write something that finds and // extracts location and temperature from the XML // data in the string page and stores them in // the strings location and temperature respectively location=find_field(page,"location"); temperature=find_field(page,"temp_c"); cout << "Location: "<<location << endl; cout << "Temperature: " << temperature << endl; system("pause"); } string find_field(string myPage,string find_string){ int temp=myPage.find(find_string); if(temp!=string::npos) { cout << "Match found at " << temp << endl; } return "found?"; } ///
List the types of polymorphism in c++?
What is the difference between while and do while loop?
What is the stack?
STL 
