C++ Tutorial Index

C++ Tutorial C++ History C++ Installation C++ First Program C++ cin and cout C++ Data type C++ Variable C++ operator C++ Keywords

C++ Control Statements

C++ If C++ Nested if C++ If-else C++ If-else-if C++ Switch C++ Break C++ Continue C++ Goto C++ For loop C++ While loop C++ Do while loop

C++ Functions

C++ Call by Value C++ Call by Reference C++ Recursion Function C++ Inline function C++ Friend function

C++ Arrays

Single dimension array Two dimension array

C++ Strings

C++ Strings

C++ Inheritance

C++ Inheritance Single level Inheritance Multilevel Inheritance Multiple Inheritance Hierarchical Inheritance Hybrid Inheritance

C++ Polymorphism

C++ Polymorphism C++ Overloading C++ Overriding C++ Virtual Function

C++ Pointers

C++ Pointers C++ this pointer

C++ Exception Handling

C++ Exception Handling

C++ Constructors

C++ Constructors Default Constructor Parameterize Constructor Copy constructor Constructor Overloading Destructor

C++ File Handling

C++ File Handling C++ Writing to file C++ Reading file C++ Close file

Miscellaneous

C Vs C++ C++ Comments C++ Data Abstraction C++ Identifier C++ Memory Management C++ Storage Classes C++ Void Pointer C++ Array To Function C++ Expressions C++ Features C++ Interfaces C++ Encapsulation std::min in C++ External merge sort in C++ Remove duplicates from sorted array in C++ Precision of floating point numbers Using these functions floor(), ceil(), trunc(), round() and setprecision() in C++ C++ References C++ Friend Functions C++ Mutable keyword Unary Operators in C++ Initialize Array of objects with parameterized constructors in C++ Differences between #define & const in C/C++ C++ Program to Implement Shell Sort C++ Program to Implement Merge Sort Storage Classes in C Vector resize() in C++ Passing by Reference Vs. Passing by the pointer in C++ Free vs delete() in C++ goto statement in C and C++ C++ program to read string using cin.getline() C++ String Concatenation Heap Sort in C++ Swap numbers in C++ Input Iterators in C++ Fibonacci Series in C++ C ++ Program: Alphabet Triangle and Number Triangle C++ Program: Matrix Multiplication C++ Program to Print Fibonacci Triangle Stack in C++ Maps in C++ Queue in C++ C++ Bitset C++ Algorithms Priority Queue in C++ C++ Multimap C++ Deque Function Pointer in C++ Sizeof() Operators in C++ C++ array of Pointers free() Vs delete in C Timsort Implementation Using C++ CPP Templates C++ Aggregation C++ Enumeration C++ Math Functions C++ Object Class C++ Queue Initialize Vector in C++ Vector in C++ C++ STL Components Function overloading in C++ C++ Maximum Index Problem C++ find missing in the second array C++ Program to find the product array puzzle C++ Program To Find Largest Subarray With 0 Sum C++ Program To Move All Zeros To The End Of The Array C++ Program to find the element that occurs once C++ Program to find the largest number formed from an array Constructor Vs Destructor C++ Namespaces C++ OOPs Concept C++ Static C++ Structs C++ Try-Catch C++ User Defined Exceptions C++ Virtual Destructor C++ vs C# Malloc() and new in C++ Palindrome Number Program in C++ Snake Code in C++ Splitting a string in C++ Structure Vs Class in C++ Virtual Function Vs Pure Virtual Function C++ Bidirectional Iterators C++ Forward Iterators C++ Iterators C++ Output Iterators C++ Range-based For Loop Converting string into integer in C++ LCM Program in C++ Type conversion in C++ Add two numbers using the function in C++ Advantage and disadvantage friend function C++ Armstrong Number Program in C++ ATM machine program in C++ using functions Binary to Decimal in C++ Bit Manipulation in C++ C++ Constructor C++ Dijkstra Algorithm Using the Priority Queue C++ int into String C++ Signal Handling Decimal to Binary in C++ Decimal to Hexadecimal in C++ Decimal to Octal in C++ Factorial Program in C++ Function in C++ Hexadecimal to Decimal in C++ Octal to Decimal in C++ Reverse a Number in C++ Structure Vs Class in C++ C++ Forward Iterators C++ Output Iterators C++ Prime number program Char Array to String in C++ Constructor Overloading in C++ Default arguments in C++ Different Ways to Compare Strings in C++ Dynamic Binding in C++ Program to convert infix to postfix expression in C++ SET Data Structure in C++ Upcasting and Downcasting in C++ Reverse an Array in C++ Fast Input and Output in C++ Delete Operator in C++ Copy elision in C++ C++ Date and Time C++ Bitwise XOR Operator Array of sets in C++ Binary Operator Overloading in C++ Binary Search in C++ Implementing the sets without C++ STL containers Scope Resolution Operator in C++ Smart pointers in C++ Types of polymorphism in C++ Exception Handling in C++ vs Java Const Keyword in C++ Type Casting in C++ Static keyword in C++ vs Java Inheritance in C++ vs Java How to concatenate two strings in C++ Programs to Print Pyramid Patterns in C++ swap() function in C++ Structure of C++ Program Stringstream in C++ and its applications rand() and srand() in C / C++ C++ Ternary Operator C++ Scope of Variables While Loop Examples in C++ Star pattern in C++ using For Loops For Loop Examples in C++ Do-While Loop Examples in C++ Top 5 IDEs for C++ That You Should Try Once Assertions in C/C++ C++ Convert Int to String Continue in C++ While loop Diamond Pattern in C++ using For Loop How to Reverse a String in C++ using Do-While Loop How to Reverse a String in C++ using For Loop How to Reverse a String in C++ using While Loop Infinite loop in C++ Loops in C++

C++ Output Iterators

Iterators :

Iterators serve as a link between algorithms and STL containers, allowing the data inside the container to be modified. They let you to iterate through the container, access and assign values, and apply various operators to them in order to get the required outcome.

Output iterators :

The Output Iterator is a C++ iterator that is commonly used to alter the value in the container. Dereference is used to change the value of a container output iterator. The Output iterator does not allow you to read the value from container. One-way and write-only iterators are commonly referred to as output iterators. In general, output iterators in C++ can be increased, but not decremented. Assignment operator(=), increment operator(++), and decrement operator(--) are the operators that may be used for an output iterator in general.

The aim of output iterators is the polar opposite of that of input iterators. This iterator is used for output operations in a sequential manner. In other words, it is employed in the assignment of values. However, it is unable to access the values. It is a companion to the input iterators, which allow you to access but not assign values. It is a one-way iterator, just as the input iterator. You can only increase the iterator once you've assigned a value, and you can't decrease the output iterator in any manner.

Types of Output iterators :

In general, an Output Iterator has two major subclasses, as shown below:

  • Insert iterator
  • Ostream iterator

Insert Iterator :

The insert iterator is a type of iterator that is used to place an element at a certain location. An assignment operator inserts the new element at the current place on the insert iterator.

Syntax :

template<class Container, class Iterator>
insert_iterator<container> inserter(Container &c,Iterator itr);

Components :

The arguments of the insert iterator's syntax are as follows:

c : This is where the new element is usually placed.

itr : It is an iterator object that normally points towards the spot that has to be changed.

Example :

#include <iostream>  
#include <iterator>    
#include <vector>     
#include <algorithm>  
using namespace std;  
int main() {  
  vector<int> v1,v2;  
  for (int k=10; k<=15; k++)  
  {   
  v1.push_back(k);   
  v2.push_back(k+2);  
  }  
 vector<int>::iterator itr = v1.begin();  
  advance (itr,3);  
 copy (v2.begin(),v2.end(),inserter(v1,itr));  
  cout<<"Elements of v1 are :";  
  for (  itr = v1.begin(); itr!= v1.end(); ++itr )  
  cout << ' ' << *itr;  
  cout << '\n';  
  return 0;  
}  

Output :

Elements of v1 are : 10 12 13 13 14 15 16 17 14 15                           

Explanation :

In the above example, output iterator is used for output operations in a sequential manner. In other words, it is employed in the assignment of values. However, it was is unable to access the values. It is a companion to the input iterators, which allow you to access but not assign values. We could only increase the iterator once we have assigned a value, and we can't decrease the output iterator in any manner as shown.

2. Ostream iterator :

The ostream iterator is a type of output iterator that is commonly used to write to the output stream like cout in a sequential manner. The basic ostream object is used to generate an ostream iterator. When the ostream operator is used with an assignment operator, a new element is usually added to the output stream.

Syntax :

template<class Tc, class charTc=char, class traits=char_traits<charT>> class

Components :

The following are the arguments of the ostream iterator's syntax:

Tc : It refers to the sort of items that will be placed in a container.

charTc : This specifies the type of items that the ostream may handle.

Character features : These are the character traits that the stream is capable of handling for the elements.

Example :

#include <iostream>  
#include<iterator>  
#include<vector>  
#include<algorithm>  
using namespace std;  
int main()  
{  
   vector<int> vec;  
   for(int x=6;x<=10;x++)  
   {  
       vec.push_back(x*10);  
   }  
 ostream_iterator<int> out(cout,", ");  
 copy(vec.begin(),vec.end(),out);  
    return 0;  
}  

Output :

60, 70, 80, 90, 100

Explanation :

In the above example, we used the ostream iterator. We introduced a vector list named vec. Further with a for loop, we used the ostream iterator in order to print the output required.

Properties Of Output Iterator :

Here are some of the outstanding features given by the Output iterator.

Equality/Inequality operator :

The output iterator cannot be compared with an equality or inequality operator.

Dereferencing :

The output iterator can really be typically dereferenced for the value of a lvalue.

Incrementable :

The output iterator may be incriminated simply by using the operator(++) function.

Drawbacks of Output Iterator :

The following are the limits that are applicable to the output Iterator in general:

  • Assigning but not accessing:
    We can allocate an output iterator as a lvalue, but programmers will not be able to access it as a rvalue.
  • Can't be decremented:
    We may often increase the output iterator by using the operator(++) method, but it cannot be decremented.
  • Multi-pass algorithm:
    In C++, you can't use an output iterator as a multi-pass algorithm. Because an output iterator is unidirectional and can only travel in one way, it can't be used to proceed through the container numerous times.
  • Relational Operators:
    When programmers use any of the relational operators, the output iterators cannot be compared.
  • Arithmetic Operators:
    Because the output iterator can only go ahead in a sequential fashion, it cannot be used with arithmetic operators.



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