Skip to main content

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:
C++ programming language provides the following types of loop to handle looping requirements.
Loop TypeDescription
while loopRepeats a statement or group of statements while a given condition is true. It tests the condition before executing the loop body.
for loopExecute a sequence of statements multiple times and abbreviates the code that manages the loop variable.
do...while loopLike a while statement, except that it tests the condition at the end of the loop body
nested loopsYou 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. Click the following links to check their detail.
Control StatementDescription
break statementTerminates the loop or switch statement and transfers execution to the statement immediately following the loop or switch.
continue statementCauses the loop to skip the remainder of its body and immediately retest its condition prior to reiterating.
goto statementTransfers 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.

Comments

Popular posts from this blog

PERL Some good framework

1. Catalyst is the most popular agile Perl MVC web framework that encourages rapid development and clean design without getting in your way. Catalyst | Perl MVC web application framework 2. Mojolicious is a next generation web framework for the Perl programming language. Back in the early days of the web, many people learned Perl because of a wonderful Perl   ... Mojolicious - Perl real-time web framework 3. Documents for Perl  The Perl Archive Network, the gateway to all things Perl. The canonical location for Perl code and modules. The Comprehensive Perl Archive Network - www. cpan .org

C++ How to use Date and Time

The C++ standard library does not provide a proper date type. C++ inherits the structs and functions for date and time manipulation from C. To access date and time related functions and structures, you would need to include <ctime> header file in your C++ program. There are four time-related types: clock_t, time_t, size_t , and tm . The types clock_t, size_t and time_t are capable of representing the system time and date as some sort of integer. The structure type tm holds the date and time in the form of a C structure having the following elements: struct tm { int tm_sec ; // seconds of minutes from 0 to 61 int tm_min ; // minutes of hour from 0 to 59 int tm_hour ; // hours of day from 0 to 24 int tm_mday ; // day of month from 1 to 31 int tm_mon ; // month of year from 0 to 11 int tm_year ; // year since 1900 int tm_wday ; // days since sunday int tm_yday ; // days since January 1st int tm_isdst ; // hours of daylight savin...

Lambda Function with Amazon DynamoDB

DynamoDB can trigger AWS Lambda when the data in added to the tables, updated or deleted. In this chapter, we will work on a simple example that will add items to the DynamoDB table and AWS Lambda which will read the data and send mail with the data added. Requisites To use Amazon DB and AWS Lambda, we need to follow the steps as shown below − Create a table in DynamoDB with primary key Create a role which will have permission to work with DynamoDBand AWS Lambda. Create function in AWS Lambda AWS Lambda Trigger to send mail Add data in DynamoDB Let us discuss each of this step in detail. Example We are going to work out on following example which shows the basic interaction between DynamoDB and AWS Lambda. This example will help you to understand the following operations − Creating a table called customer in Dynamodb table and how to enter data in that table. Triggering AWS Lambda function once the data is entered and sending mail using Amazon SES service. The basic block diagram that ...