Skip to main content

Looping Constructs used in C langeuage:-

    In any programming language loops are used to execute a set of statements repeatedly until a particular condition is satisfied. 
    
    The loop directs a program to perform a set of operations again and again until a specified condition is true. Looping statement is used when we want to execute statements until a condition is true.C contains following type of looping statement:-
* The for loop
* The while loop
* The do-while loop


  * For loop:-
           for loop is used to execute a set of statements for a given number of times , means if we want to execute statements till a certain number of time , for loop is used.
  Syntax:
                 for(start value; end value ; increment/decrement)
                   {
                          statement;
                      }

The for loop is commonly used when the number of iteration is known. So a for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.
   A for loop has two parts:- a header specifying the iteration. And a body which is executed once per iteration. The header often declares an explicit loop counter or loop variable, which allows the body to know which loops are typically used when the number of iteration is known before entering the loop. for loops can be thought of as shorthands for while-loops which increment and test a loop variable.



* While loop:-
              A while loop statement contains the condition first. If the control executes the statements of the while loop else, it ignores these statements.
   Syntax:
                while(condition)
                  {
                       Statement;
                    }

A while loop in C programming repeatedly executes a target statement as long as a given condition is true. When the condition becomes false,the line immediately following the loop.
    The while construct consists of a block of code and a condition.The condition is evaluated,and if the condition is true , the code within the block is executed.This repeats until the condition becomes false. Because the while loop checks the condition before the block is executed.



*Do-While loop:-
                    Do-while loop statement is another method used in C programming. Do - while loop ensures that the program is executed at least once and checks whether the condition at the end of the do-while loop is true or false.As long as the test condition is true,the statements will be repeated.

Syntax:
            do
               {
                     Statement;
                } while(condition);

 In most computer programming language, a do-while loop is control flow statement that executes a block of code at least once, and then repeatedly on a given boolean condition at the end of the block.
       The do -while construct consists of a process symbol and a condition.first,the code within the block is evaluated.If the condition is true the code within the block is executed again.This repeats until the condition becomes false.


One more loop which is not categorised is infinite loop.
    * Infinite loop:-
                      An infinite loop is sequence of instructions in a computer program which looks endlessly, either due to loop having no terminating condition , having one that can never be met or one that cause the loop to start over. Infinite loops are possible cause for a computer "freezing" other include thrashing,deadlock and access voidation. 


Therefore, loops are one of the most powerful concepts of computer programming facilitating the programmers or software developers to create such software modules or programs that are effective and efficient and to meet the requirement of the business needs.

Comments

Post a Comment

Please comment.

Popular posts from this blog

Process & Its state And process control block :-

                ⇰  PROCESS :- A process can be thought of as a program in execution. Means when any program is executed it becomes process. A processwill need certain resources such as CPU time , memory, files and I/O devices to complete its task. These resources are allocated to the process either when it is created or at the time of execution.             A process is the unit of work in most systems. A system consistes of a collection of processes. All these processes may execute concurrently. Traditionally a process contained only a single thread. Most modern operating ststems now supports processes that have multiple threads.         The operating system is responsible for several important works of process management as - the creation and deletion of process, the schrduling of process, communication and deadlock handling of process. Process is broudly divided into two ...

Process Scheduling And Types of Process Schedular :-

        ⇰ PROCESS SCHEDULING Process Scheduling  is a task  of Operating System that schedules processes of different states like new, ready, waiting, terminated  and running.This scheduling helps in allocation of CPU time for each process, and Operating System allocates the CPU time for each procss. And the process scheduling plays important role to keep the CPU busy all the time.  ⏩   Followings are some objectives of Process Scheduling :-  i > To increase the amount of users within acceptable response times.  ii > To maintain the balance between response and utilization of system. iii > To decrease the enforce priorities and  give reference to the processes holding the key resources.      ⇰  PROCESS SCHEDULAR A scheduler carries out the pro cess scheduling work. Schedulers are often implemented so they keep all computer resources busy and  allows multiple users to shar...

Atomic Transaction In Operating System

All the synchronization techniques we have studied are essentially low level as like semaphores. They require the programmer to involved with all the details of mutual exclusion, critical region management, deadlock prevention, and crash recovery. An abstraction exists there  and is widely used in distributed systems. We will call it an  atomic transaction,  or simply  transaction.   The term  atomic action  is also widely used. The mutual exclusion of critical section ensures that the critical sections are executed automatically. That is, if two critical sections are executed concurrently, the result is equivalent to their sequential execution in some unknown order.   In many cases we would like to make sure that a critical section forms a single logical unit of work that either is performed in its entirely or is not performed at all. An example is funds transfer, in which one account is debited and another is credited. Clearly, it is essential f...