Tuesday, December 19, 2017


C++ Loop Types

There may be a situation, when you need to execute a block of code several number of times. In general, statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.
Programming languages provide various control structures that allow for more complicated execution paths.
A loop statement allows us to execute a statement or group of statements multiple times and following is the general from of a loop statement in most of the programming languages −
Loop Architecture C++ programming language provides the following type of loops to handle looping requirements.
Sr.No Loop Type & Description
1 while loop Repeats a statement or group of statements while a given condition is true. It tests the condition before executing the loop body.
2 for loop Execute a sequence of statements multiple times and abbreviates the code that manages the loop variable.
3 do...while loop Like a ‘while’ statement, except that it tests the condition at the end of the loop body.
4 nested loops You can use one or more loop inside any another ‘while’, ‘for’ or ‘do..while’ loop.

Loop Control Statements

Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed.
C++ supports the following control statements.
Sr.No Control Statement & Description
1 break statement Terminates the loop or switch statement and transfers execution to the statement immediately following the loop or switch.
2 continue statement Causes the loop to skip the remainder of its body and immediately retest its condition prior to reiterating.
3 goto statement Transfers control to the labeled statement. Though it is not advised to use goto statement in your program.

The Infinite Loop

A loop becomes infinite loop if a condition never becomes false. The for loop is traditionally used for this purpose. Since none of the three expressions that form the ‘for’ loop are required, you can make an endless loop by leaving the conditional expression empty.
#include <iostream>
using namespace std;
 
int main () {
   for( ; ; ) {
      printf("This loop will run forever.\n");
   }

   return 0;
}
When the conditional expression is absent, it is assumed to be true. You may have an initialization and increment expression, but C++ programmers more commonly use the ‘for (;;)’ construct to signify an infinite loop.
NOTE − You can terminate an infinite loop by pressing Ctrl + C keys.



source:https://www.tutorialspoint.com
 C++ for beginner

C++ is a middle-level programming language developed by Bjarne Stroustrup starting in 1979 at Bell Labs. C++ runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX. This tutorial adopts a simple and practical approach to describe the concepts of C++.

Audience

This tutorial has been prepared for the beginners to help them understand the basic to advanced concepts related to C++.

Prerequisites

Before you start practicing with various types of examples given in this tutorial,we are making an assumption that you are already aware of the basics of computer program and computer programming language.

Execute C++ Online

For most of the examples given in this tutorial you will find Try it option, so just make use of this option to execute your C++ programs at the spot and enjoy your learning.
Try following example using Try it option available at the top right corner of the below sample code box −
#include <iostream>
using namespace std;

int main() {
   cout << "Hello World";
   return 0;