The loop Control Structure

Question 1

3 Methods to loop:

Answer 1

1. For statement
2. While Statment
3. do-while

Question 2

while statement:

Answer 2

initialise loop counter (index variable);
while (Condition [to test loop counter or any Exp] )
{ body of while;
loop counter increment / decrement;
}

loop counter can be float as well, u can incre or decree them by a float value.

Question 3

Default scope of while

Answer 3

1 statement right after it.

Question 4

Output?
int i = 1;
while ( i<= 32767 )
{
   printf("hi");
   i++
}

Answer 4

Indefinite.
when is 32767 and reaches increment, it wants to become 32768 which falls out of int range so instead it becomes -32768 and it satisfies the while condition, this will keep on happening.

Question 5

OutPut?
int i = 1;
while ( i<= 10 );
{
   printf("hi");
   i++
}

Answer 5

Indefinite
int i = 1;
while ( i<= 10 )
         ;
{
   printf("hi");
   i++
}
No output but control keeps rotating as i is not incremented.

Question 6

Compound Assignment Operator:

Answer 6

+= , -=, *=, /=, %=.

Question 7

While(i++ < 10)

Answer 7

post increment operator. Performs i < 10 and then i becomes i + 1, for the body of loop for tht cycle and next check.

Question 8

++i

Answer 8

First ‘i’ gets incremented and then its Exp is evaluated.

Question 9

The for loop:

Answer 9

for ( initialise counter ; test counter ; increment counter)
{
excute statements;
}

Initialization, testing & increment incorporated in for statement.
those three can be any expressions, remember the flow of control.

Question 10

Working of For:

Answer 10

set counter value, test condition execute the body and then increment.

Question 11

Default Scope of For:

Answer 11

Immediately next statement after it.

Question 12

is this Valid:
for ( ;i++ >10; ){
}

Answer 12

Note semicolons are necessary.

here the comparison is done then the value is incremented and then body of the loop is executed.

Question 13

Nesting for loops.

Answer 13

For each value of outer loop, inner loop will take all values.

Question 14

Multiple Initialisations in the for loop.

Answer 14

for ( i = 1 , j = 0 ; j < 2 ; i++, j++ ) {statement;}
test expression can be only one but u can use logical operators to link more conditions.
hence ; are used in for statement so , allow us to use multiple initialisation n increment.

Question 15

The odd Loop

Answer 15

When we unaware how many times to loop

use of do-while.

Question 16

break statement:

Answer 16

When ‘break’ is encountered the control is passed to the statement just after the loop its executing in.

Question 17

Find a prime number.

Answer 17

pg 118.

Question 18

The continue Statement:

Answer 18

On encounter of continue in a loop, the control is passed to the beginning of the loop, skipping the body after continue.

Question 19

The Do-While loop:

Answer 19

do
{
statement(s);
}
while( condition );

here body is necessarily executed at least once.

Question 20

break and continue in do while:

Answer 20

break will send u to after condition.

Continue will send u to end at the condition and execute it.