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In the previous chapter, you have learned what are variables, data types in programming, sequence,
loop, bug, event and collections. In this chapter, you will learn about control structures, functions,
arrays and sequencing with loops and conditions.
What are Control Structures?
Control structure is a coding construct that is used to decide the flow of a program based on the
parameters given to it. Usually, a control structure accepts and analyses a variable to make a
decision on which direction to proceed. So, the control structure is a basic decision-making process
in computing.
• Sequential: Statements in a program are executed sequentially or step-by-step in an order in
which the instructions are written.
• Selection/Conditional: It is used to test a condition in a program. It takes decision to execute
one statement/operation over another statement/operation depending on the condition.
• Iteration: It executes set of statements for a certain number of times till the given condition is
true. Example: Loops
On the basis of the above three control structures, programming has derived many types of control
statements to suit different needs.
Understanding IF-ELSE and ELSE-IF statements
Every day, you take many decisions depending on the situation. For example, if you are given a
number and you need to check if the number is even or odd, you will check this by dividing the
number with 2. If the remainder is 1, the number is odd and if the remainder is 0, then the number
is even.
IF-ELSE Statement
Let us look at an example first.
Example: To check if a number is even or odd by using if-else Information Literacy
statement.
Flowchart:
Start
Read Num1
Is the number No
The number is odd
divisible by 2?
Yes
The number is even
End
62 DigiCode AI-VIII

