Modular programming involves dividing a program into smaller, manageable modules. The main module contains the program entry and exit points, while sub-modules perform specific tasks controlled by the main module. There are two types of procedures in modular programming - SUB procedures, which do not return values, and FUNCTION procedures, which return a single value. Parameters allow data to be passed into procedures to perform operations and return results. Modular programming offers benefits like reduced code, improved readability and maintainability, and ability to test modules independently.

1. Modular Programming
Chapter-9
Class-10
Presenter By: Bhuwan Bist
Computer Teacher,
Adarah Vidya Niketan Secondary
School
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2. Overview
• Modular programming is a technique used to divide our
program into many small, manageable and functional
module or block.
• Every modular program has one main module and many sub
module. The sub module of a program is also called as a
procedure.
• Main module is the top level module in which program entry
and exit takes place.
•Sub-Module is a block of statement that is used for specific
task and controlled by main module. Click to adBhuwan_Bista

3. Structure of Modular Programming
Main
Program-M1
Module-M2
Module-M6 Module-M7
Module-M3 Module-M4 Module-M5
Module-M8
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4. Advantages of Modular program
It reduces program codes.
 Increases the readability of program.
 Easy to debug program.
 Program maintenance become easier.
Module can be tested independently
Saving the time during project development.
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5. Types of Procedure in Qbasic Program
In Qbasic, a programmer can name a block of code can
be executed by simple calling out that name. These
name block of code are called procedures.
The two types of procedures are:
1. SUB Procedure
2. FUNCTION Procedure
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6. SUB Procedure
 A SUB Procedure is a small manageable and functional part
of program that performs specific task and does not return
any value to the calling module.
 The block of statements is placed with a pair of SUB/END
SUB statement and can be called by its name.
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7. Features of SUB Procedure
SUB procedure cannot be a part of an expression and does not
return any value.
SUB procedure do not have data type.
Argument can be passed to the subprogram by reference and
by value method.
SUB procedure name can't be used as a variable .
SUB procedure is called by CALL statement.
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8. Declaring SUB Procedure
 The DECLARE statement is used to declare a SUB procedure.
The syntax for the DECLARE statement is as follows:
DECLARE SUB name(parameter list)
Example:
DECLARE SUB volume(L,B,H)
SUB procedure volume with three parameters L,B and H
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9. Defining a SUB Procedure
oThe SUB....END SUB statement is a procedure
statement that marks the beginning and ending of a
subprogram. The syntax is:
SUB Procedure name [parameter, list]
[Statement]
END SUB
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10. Call a SUB Procedure
• The CALL statement is used to transfer control to another procedure,
a BASIC SUB program.
• The syntax is
CALL name(argument list)
Example:
CALL circumference(r)
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11. Example
• Write a program to create a sub-procedure to input the value of length,
breadth and height of a cuboid. The program should calculate the diagonal,
volume and of a cuboid.

12. FUNCTION Procedure
 A function is a small manageable and functional part of a
program that performs specific task and returns a value to the
main program or calling module.
 It is written with FUNCTON.....END FUNCTON Statements.
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13. Features of FUNCTION Procedure
⮚ FUNCTON procedure are used in expressions and can directly
returns a single value.
⮚ FUNCTION procedure have a data type which is the return
value of the function.
⮚ The parameters can be passed by reference or by value.
⮚ FUNCTION procedure can be recursive.
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14. Example
• Write a program to declare a user defined function using FUNCTION.....END
FUNCTION to print the area of a triangle by using expression method.
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15. The difference between Function procedure and SUB
procedure
SUB Procedure FUNCTION Procedure
The block of statement Is placed with a pair of
a SUB/END SUB statement and be called by
name.
The block of statement is placed with a pair of
FUNCTION/END FUNCTION statements and be
invoked from the reference of the function
name.
It dies nit return any value . It directly returns a single value
It does not have a data type It has a data type which is the return value of
the function.
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16. What are parameters?
Parameters are variables that receives data (argument values)
and the procedure (SUB/FUNCTION procedure)
Arguments: The constant and variable enclosed in the
parentheses of procedure call statement and that are supplied
to a procedure and known as arguments.
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17. Thank You