Class 7 : CHAPTER 9. LOOPING STATEMENTS

DESCRIPTIVE TYPE QUESTIONS :

1. Explain the term looping.
   Ans. Looping means repeated execution of a statement or a set of statements. Looping technique is used in programming to reduce the number of instructions and also memory space. In looping , we need to keep track of the number of times loop has been executed through a control variable.
2. Define the FOR… NEXT looping statement.
   Ans. FOR… NEXT is a looping statement that has the following syntax :
   FOR = TO
   { statements }
   NEXT
   The statements in the FOR… NEXT loop will be executed until the control variable reaches the final value.
3. What is the use of STEP statement in FOR…NEXT ?
   Ans. STEP statement in FOR… NEXT statement increments or decrements the value of the control variable by the number specified after STEP statement.
   For Eg: FOR L = 1 TO 20 STEP 3 will increment value of L to 4 , 7 , 10 , 13 , 16 , 19 in successive loops.
4. What is nested loop ?
   Ans. A loop that is contained in another loop is called a nested loop.
   • All loops must have a control variable .
   • The control variable names cannot be same in the inner and outer loops.
   • There can be a maximum of nine loops inside one loop.
   • The inner loop must begin and end inside the outer loop.
5. What is the difference between WHILE…WEND and DO UNTIL ?
   Ans. WHILE … WEND is a loop type that executes the statements until the given condition is TRUE.
   Syntax : WHILE condition
   { statement(s) }
   WEND
   DO UNTIL is a loop type that executes the statements until the given condition is FALSE.
   Syntax : DO UNTIL condition
   { statement(s) }
   LOOP