QUESTION 01 · Selection

What is a control statement? Name its three main categories.

2 marks

Answer

A control statement changes the order in which statements execute. The main categories are selection, repetition and jump statements.

Selection chooses a path; repetition repeats a block.
Jump statements transfer control to another permitted point.

Explain the types of control statements in C.

5 marks

Answer in brief

Control statements decide which statements execute, how often they execute and when control moves to another part of a program.

Sequential execution

Normally, C executes statements in their written order within a block. For example, reading two values, calculating their sum and printing it is a sequence. Control statements change this flow when a problem requires a choice or repeated work.

Selection statements

if executes a block when a condition is true.
if-else chooses between two alternatives. Nested if and an else-if ladder allow several decisions.
switch selects a starting case using an integer or enumeration value.

Repetition statements

while checks a condition before each iteration.
for places initialisation, a condition and an update together.
do-while checks the condition after the body, so the body runs at least once.

Jump statements

break leaves the nearest loop or switch.
continue skips the rest of the current loop iteration.
goto transfers control to a label in the same function. return leaves the current function.

Example

A marks-processing program may use a loop to read several marks and an if-else statement to display Pass or Fail for each mark. The loop handles repetition, while the decision handles selection. Use braces to show which statements belong to each block. In a condition, zero means false and a non-zero value means true.