TUGAS PROGDAS 01 - Program Design and Pseudocode - Copy

8/6/2019 TUGAS PROGDAS 01 - Program Design and Pseudocode - Copy

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CHAPTER 1 PROGRAM DESIGN

CHAPTER 2 PSEUDOCODE

Muh Anung Darmawan 33209

Muhammad Muzani 33267


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CHAPTER 1 : PROGRAM DESIGN

To write well-designed programs, we need :

1. Right tools

2. Right steps to follow

Programming can be defined as thedevelopment of a solution to an identified

problem, and the setting up of a related series

ofinstructions which, when directed through

computer hardware, will produce the desired

results.


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STEPS IN PROGRAM DEVELOPMENT

(1)

There are seven basic steps in thedevelopment of a program

1. Define the problem. For initial analysis, the problem should be

divided into three separate components:1) the inputs

2) the outputs3) The processing steps to produce the required

outputs.

2. Outline the solution (or user interface). We decompose problem it into smaller tasks or steps


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(2)3. Develop the outline into a solution algorithm

We expand the solution outline developed in Step 2

into an algorithm: a set of precise steps that

describe exactly the tasks.

4. Test the algorithm for correctness. This step is one of the most important in the

development of a program, and we must remember

to finish this step.

The main purpose ofdesk checking the algorithm

is to identify major logic errors early,

5. Code the algorithm into a specific programming

language.

We code the program into our chosen

programming language.


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(3)6. Run the program on the computer.

We uses a program compiler and programmer

designed test data to machine test the code for syntax

errors (those detected at compile time) and logic errors

(those detected at run time).

7. Document and maintain the program.

Documentation involves both external documentation

(such as hierarchy charts, the solution algorithm and test

data results) and internal documentation that may

have been coded in the program.


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METODOLOGI DESAIN PROGRAM

The fundamental principle of program designis based on the fact that a program acceptsinput data, processes that data, and thendelivers that data as output to the program

user. Recently, a number of different approachesto program design have emerged, the mostcommon being:

1. procedure-driven process/function

2. event-driven event/interaction

3. data-driven data data structure

The choice between procedure-driven, Event-driven or Data-driven program designmethodologies is usually determined by theselection of a programming language.


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PROCEDURAL VERSUS OBJECT-ORIENTED

PROGRAMMING (1)

1. Procedural programming

y Procedural programming is based on a structured

(tasks or functions ), Top-down approach to

writing effective programs. The approach

concentrates on 'what' a program has to do and

involves identifying and organizing the 'processes'

in the program solution. The problem is usually

decomposed into separate tasks or functions and

includes 1)Top-down development and 2)modular

design.


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PROGRAMMING (2)

1) Top-down development

We, first, outline a general solution to the Problem, then broken

down gradually into more detailed steps until finally the most

detailed levels have been completed.

This systematic, disciplined approach result in a higherprecision of programming than was previously possible.

programming than was previously possible.

2) Modular design.

Procedural programming also incorporates the concept ofmodular

design, which involves grouping tasks together because they all

perform the same function (for example, calculating sales tax orprinting report headings). Modular design is connected directly to

Top-down development, as the steps or subtasks, into which

the programmer divides the program solution, actually form the

future modules of the program. Good modular design also

assists in the reading and understanding of the program.


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PROGRAMMING (3)

2. Object-Oriented Programmingy Object-oriented programming is also based on

decomposing the problem however, the primary

focus is on the things (or objects) that make upthe program. The program is concerned with how

the objects behave, so it breaks the problem into a

set of separate objects that perform actions and

relate to each other. These objects have definite

properties, and each object is responsible for

carrying out a series of related tasks.


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AN INTRODUCTION TO ALGORITHMS AND

PSEUDOCODE (1)

1. Algorithm

y An algorithm is like a recipe: it lists the steps

involved in accomplishing a task.

y The algorithm is written in simple English and is

not a formal document

y to be useful, there are some principles which should

be adhered to. An algorithm must:

1) be lucid, precise and unambiguous

2) give the correct solution in all cases

3) eventually end.


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PSEUDOCODE (2)

2. Pseudocode

y Pseudocode has been chosen as the primary method of

representing an algorithm because it is easy to read and

write and allows the programmer to concentrate on the

logic of the problem.


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PSEUDOCODE (3)

y Like many versions of pseudocode, this version has

certain conventions, as follows:

Statements are written in simple English.

Each instruction is written on a separate line.

Keywords and indentation are used to signify particularcontrol structures.

Each set of instructions is written from top to bottom, with

only one entry and one exit.

Groups of statements may be formed into modules, and

that group given a name.


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PROGRAM DATA(0)

Yang akan dibahas

y Variable, constants, lieteral

y Data types

y

Filesy Data Validation


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PROGRAM DATA(1)

Variables, constants and literals

y Variable : It is called a variable because the value

stored in those memory cells may change or vary

as the program executes

y Constant : a data item with a name and a value

that remain the same during the execution of the

program. For example, the name 'fifty' may be given

to a data item that contains the value 50.

y Literal : a constant whose name is the written

representation of its value. For example, the

program may contain the literal '50'.

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TUGAS PROGDAS 01 - Program Design and Pseudocode - Copy