4 Difference Between Entry Controlled And Exit Controlled Loop In C++

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In programming, a loop is an instruction that repeats until a specified condition is reached. In a loop structure, the loop asks a question, if the answer requires action, it is executed. The same question is asked again and again until no further action is required. Each time the question is asked it is referred to as iteration.

Usually a looping process entails:

  • Setting and initialization of a condition variables.
  • Execution of the statements in the loop.
  • Test for a specified value of the con variable for execution of the loop.
  • Incrementing or updating the con variable.

Types of Loops

Three major types of loops include:

  • A Do While Loop also referred to as Repeat Until Loop, it repeats until an expression becomes false.
  • For Loop which is a loop that runs for a preset number of times.
  •  While Loop which is a loop that is repeated as long as an expression is true. An expression is a statement that has value.

A program loop is made up of two segments, that is, the body of the loop and control statement. The control statement tests certain conditions and then directs the repeat execution of the statement s contained in the body of the loop. Now, depending on the position of the control statement in the loop, a control structure may be classified as either entry controlled loop or exit controlled loop.

What Is Entry Controlled Loop?

An entry control loop, controls entry to the loop and thus why it is referred as entry control loop.  An entry control loop checks the condition at the time of entry and if the condition or expression (statement that has value) becomes true then control transfers into the body of the loop. Examples of exit controlled loop include, For Loop and While Loop.

What You Need To Know About Entry Controlled Loop

  1. Entry controlled loop is a loop in which the test condition is checked first, and then loop body will be executed.
  2. In entry controlled loop, if the test condition is false, loop body will not be executed.
  3. Examples of exit controlled loop include, For Loop and While Loop.
  4. Entry controlled loop are used when checking of test condition is mandatory before executing loop body.

What Is Exit Controlled Loop?

An exit control loop, controls exit of the loop, thus why it is referred to as exit control loop. An exit control loop checks the condition for exit and if given condition for exit evaluate to true, control will exit from the loop body or else control will enter again into the loop. An example of exit controlled loop is Do While Loop.

What You Need To Know About Exit Controlled Loop

  1. Exit controlled loop is a loop in which the loop body is executed first and then the given condition is checked afterwards.
  2. In exit controlled loop, if the test condition is false, loop body will be executed at least once.
  3. An example of exit controlled loop is Do While Loop.
  4. Entry controlled loop is used when checking of test condition is mandatory after executing.

Also Read: Difference Between Compile Time Polymorphism And Run Time Polymorphism In C++

Between Entry Controlled And Exit Controlled Loop In Tabular Form

BASIS OF COMPARISON ENTRY CONTROLLED LOOP EXIT CONTROLLED LOOP
Description Entry controlled loop is a loop in which the test condition is checked first, and then loop body will be executed.   Exit controlled loop is a loop in which the loop body is executed first and then the given condition is checked afterwards.  
False Test Condition If the test condition is false, loop body will not be executed.   If the test condition is false, loop body will be executed at least once.
Example Examples of exit controlled loop include, For Loop and While Loop.   An example of exit controlled loop is Do While Loop.  
Use Entry controlled loop are used when checking of test condition is mandatory before executing loop body.   Entry controlled loop is used when checking of test condition is mandatory after executing.  

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