1. Data Structures and Algorithms
Pointers for
Structuring a
Program
1. Use Modules
2. Use the four logic structures
a. Sequential Structure
b. Decision Structure
c. Loop Structure
d. Case Structure
3. Eliminate the rewriting of identical processes by
using modules
4. Use techniques to improve readability, including
the four logic structures, proper naming of
variables, internal documentation, and proper
indentation
Introduction to Programming Structure *Property of STI
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2. Data Structures and Algorithms
Cohesion and
Coupling
Cohesion
@ relates to the functional independence of the
module and to the performance of a single “task”
within the module
Coupling
@ allows modules to be connected by an interface,
which enables the programmer to transfer data
from one module to another.
Introduction to Programming Structure *Property of STI
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3. Data Structures and Algorithms
Modules
Rules in Designing Modules
1. Each module is an entity itself.
2. Each module has a single function.
3. Each module is short enough to be easily read and
modified.
4. The length of a module is governed by its function
and the number of instructions to be executed to
perform that function.
5. A module is developed to control the order of
processing.
Introduction to Programming Structure *Property of STI
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4. Data Structures and Algorithms
Modules
Types of Modules
1. Control Module
2. Initialization Module
3. Process Data Module
a. Calculation Modules
b. Print Modules
c. Read and Data Validation Modules
4. Wrap-up module
5. Event Modules (OO-Paradigm)
Introduction to Programming Structure *Property of STI
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5. Data Structures and Algorithms
Local and Global
Variables
Local Variables
@ may be used only by the module itself
Global Variables
@ they are global to the program as they can be seen by
all modules
Introduction to Programming Structure *Property of STI
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6. Data Structures and Algorithms
Parameters
Parameters
@ local variables that are passed or sent from one
module to another. Parameters are another way
of facilitating coupling that allows the
communication of data between modules
Calling Module
@ the module that processes another module
Called Module
@ the module being processed
Introduction to Programming Structure *Property of STI
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7. Data Structures and Algorithms
Parameters
Actual parameter listing
@ the list of parameters that follows the module
name being processed in the calling module
Formal Parameter Listing
@ the list of parameters that follow the module
name at the beginning of the module
Introduction to Programming Structure *Property of STI
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8. Data Structures and Algorithms
Parameters
Types of parameter passing
a Call by value
a Call by reference
Introduction to Programming Structure *Property of STI
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9. Data Structures and Algorithms
Parameters
Introduction to Programming Structure *Property of STI
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10. Data Structures and Algorithms
Parameters
Introduction to Programming Structure *Property of STI
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11. Data Structures and Algorithms
Variable Names
and Data
Dictionary
The Four Logic Structures
• Sequential
• Decision
• Loop
• Case
Introduction to Programming Structure *Property of STI
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