Programming 1_Lecture 1

7/25/2019 Programming 1_Lecture 1

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Lecture 1

Introduction to Programming

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Programming 1


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Outline

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Module Overview MOODLE & Enrolment Key

Syllabus / Schedule Outline


A Simple Example Introduction to QBasic

Data Variables and Constants Commands for our pseudocode and equivalents in QBasic Syntax for our pseudocode and equivalents in QBasic

Mathematical Calculations Functions

More Example(s)


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Module Overview

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The Big Picture! (Programming as a component of Computing) This module is primarily designed to help the student develop the

problem solving skills required for building software.

Programming is useless without problem solving

GIGO

First we focus on problem solving by algorithm development and we usesome tools to help us with that: Lecture/Tutorial: Pseudocode and Flowcharts for algorithms Lecture/Tutorial: Tracetables for testing In the Lab: Write QBasic code for some of our algorithms to help bring our

solutions to life In the Lab: Flowrunner to help with our flowcharting skills

Once we have learned the constructs that we need we focus on anintroduction to C programming for the last 3 weeks of the module

Success in the Module


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MOODLE

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utechonline.utech.edu.jm

Faculty of Engineering & Computing

School of Computing & Information Technology

Programming 1

Enrolment key


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System Development Life Cycle (SDLC) Is a series of well-defined steps that should be followed when a

system is created or being changed.

Represents the big picture of what happens during system

creation or modification.


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The SDLC contd.

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The System Development Life Cycle is comprised of 6 steps,namely:

Analyze the current system

Define the new system requirements

Design the new system

Develop the new system

Implement the new system

Evaluate the new system


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The Program Development Cycle (PDC)

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The fourth step of the SDLC (Development of the newsystem) is comprised of a series of well-defined steps called

the Program Development Cycle.

A programmer carries out the steps in the PDC.


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Steps of the PDC

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The steps are outlined as follows: Review the input, processing, output and storage requirements

(IPOS)

Develop the logic for the program

Test the logic for correctness

Write the program using a programming language

Test and debug the program

Complete the program documentation


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What is a program?

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A program is an organized list of instructions that, whenexecuted, causes the computer to behave in a predetermined

manner. Without programs, computers are useless.


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What is Programming?

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Programming is the process of instructing the computer toaccomplish a particular task.

It is done with the help of a programming language.

When the program is executed, the instructions will be

converted into machine language, which is the only language

that the computer understands.

Programmer vs. User (Think behind the scenes!)


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Languages we will use

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In this course we will use QBasic and C

These are both high level programming languages

These languages were developed so that one single statement

could be written to accomplish substantial tasks and in so

doing speed up the programming process.

For the computer to understand these languages a translator

program (called an interpreter in the case of QBasic or a

compiler in the case of C) converts them into machinelanguage


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Example 1.1 and some points to note!

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Write a program that accepts any two integer numbers fromthe user and displays the sum of these two numbers.

We need to first write an algorithm

Flowcharts

Pseudocode Each algorithm can be tested using a trace table

Then we will convert this algorithm to a program usingQBasicsimilar to pseudocode; makes it easier for you to

focus on problem solving We will avoid C until we have covered the important

constructs and problem solving skills


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Pseudocode

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BEGIN

DECLARE number1, number2 and sum as integers

PRINT "Please enter the first number"

INPUT number1

PRINT "Please enter the second number"INPUT number2

LET sum = number1 + number2

PRINT number1; +;number2; is; sum

END


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Flowchart

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Start

Declare number1,

number2, sum as

Integer

Print Enter the first

number

Input number1

Print Enter the

second number

Input number2 sum=number1+number2

Print number1, +,

number2, is, sum

Stop


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The QBASIC Program

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Lets run this program using QbasicThe Qbasic code looks like this:

Discussionthe mapping between the QBASIC program and ouralgorithmic solutions

' BEGIN

DIM number1, number2, sum AS INTEGER

PRINT "Please enter the first number"INPUT number1

PRINT "Please enter the second number"

INPUT number2

LET sum = number1 + number2

PRINT number1; "+"; number2; "is"; sum

END


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Introduction to QBasic

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BASIC stands for Beginners All-purpose SymbolicInstruction Code

It was invented in 1963, at Dartmouth College, by the

mathematicians John George Kemeny and Tom Kurtzas. Microsoft version Quick Basic (QBasic)

QBASIC is an interpreter

it reads every line translates it and lets the computer

execute it before reading another.


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Features of QBasic

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It is a user friendly language.

It is a widely known and accepted programming

language.

Language is easy since the variables can be named easilyand uses simple English phrases with mathematical

expressions.


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Rules of QBasic

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All QBasic programs are made up of series ofstatements, which are executed in the order in which

they are written.

Every statement should have at least one QBasiccommand word. The words that QBASIC recognizes are

called keywords.

All the command words have to be written using some

standard rules, which is the syntax associated with thecommand. Syntax is the grammar of writing the statement in a language. Syntax

errors are generated when improper syntax is detected.


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Next Class

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Programming Concepts Memory

Variables

Identifiers etc.

Control Structures

Sequence

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Programming 1_Lecture 1