Question

In pseudocode, consider the DOWHILE repetition control structure. Control passes to the next statement after the delimeter ENDDO (and no further processing takes place within the loop) when which of the following occurs? a condition p is found to not evaluate to true or false a condition

p is found to be true

a condition p is found to null

None of the other answers are correct

a condition p is found to be false

Answer 1

ans) a condition p is found to be false

explaination:

Like while the do-while loop execution is also terminated on the basis of a test condition. The main difference between a do-while loop and while loop is in the do-while loop the condition is tested at the end of the loop body, i.e do-while loop is exit controlled whereas the other two loops are entry controlled loops.

Syntax:

do
{
   // loop body

   update_expression;
} 
while (test_expression);

The various parts of the do-while loop are:

1. Test Expression: In this expression we have to test the condition. If the condition evaluates to true then we will execute the body of the loop and go to update expression. Otherwise, we will exit from the while loop.
   Example:

   i <= 10

2. Update Expression: After executing the loop body, this expression increments/decrements the loop variable by some value.
   Example:

   i++;

How does a do-While loop executes?

1. Control falls into the do-while loop.
2. The statements inside the body of the loop get executed.
3. Updation takes place.
4. The flow jumps to Condition
5. Condition is tested.
   1. If Condition yields true, goto Step 6.
   2. If Condition yields false, the flow goes outside the loop
6. Flow goes back to Step 2.

Flow Diagram do-while loop:

// C++ program to illustrate do-while loop 

#include <iostream> 
using namespace std; 

int main() 
{ 
        // Initialization expression 
        int i = 2; 

        do { 
                // Loop body 
                cout << "Hello World\n"; 

                // Update expression 
                i++; 

        } 
        // Test expression 
        while (i < 1); 

        return 0; 
} 

Output:

Hello World

Dry-Running Example 1:

1. Program starts.
2. i is intialised to 2.
3. Execution enters the loop
  3.a) "Hello World" gets printed 1st time.
  3.b) Updation is done. Now i = 2.
4. Condition is checked. 2 < 2 yields false.
5. The flow goes outside the loop.

// C program to illustrate do-while loop 

#include <stdio.h> 

int main() 
{ 
        // Initialization expression 
        int i = 1; 

        do { 
                // Loop body 
                printf("%d\n", i); 

                // Update expression 
                i++; 

        } 
        // Test expression 
        while (i <= 5); 

        return 0; 
} 

Output:

1
2
3
4
5