Cours

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Contents

CONTENTS........................................................................................................................................................... 3

LIST OF FIGURES .............................................................................................................................................. 5

LIST OF TABLE .................................................................................................................................................. 7

CHAPTER 1. INTRODUCTION TO COMPUTER SCIENCE................................................................. 8

1.1 INTRODUCTION .................................................................................................................................................... 8

1.2 DEFINITION OF COMPUTING (INFORMATICS)........................................................................................................ 8

1.3 DEFINITION OF A COMPUTER ............................................................................................................................. 10

1.4 EVOLUTION OF INFORMATICS AND COMPUTERS ................................................................................................ 11

1.5 INFORMATION ENCODING SYSTEMS ................................................................................................................... 16

1.6 NUMBER SYSTEMS............................................................................................................................................. 16

1.6.1 Binary language in computing.................................................................................................................. 17

1.6.2 Multiple bits: ............................................................................................................................................ 17

1.6.3 the storage capacity of a memory ............................................................................................................. 18

1.6.4 Use of the byte (the ASCII code): ............................................................................................................. 19

1.7 THE PRINCIPLE OF OPERATION OF A COMPUTER ................................................................................................. 20

1.8 HARDWARE COMPONENTS OF A COMPUTER:...................................................................................................... 22

1.9 THE BASIC SYSTEMS OF A COMPUTER ................................................................................................................ 26

1.9.1 Operating System (OS):............................................................................................................................ 26

1.9.2 Programming languages .......................................................................................................................... 31

1.9.3 Application software ................................................................................................................................. 34

CHAPTER 2. ALGORITHM AND PROGRAM CONCEPTS .................................................................39

2.1 INTRODUCTION .................................................................................................................................................. 39

2.2 PROBLEM AND STATEMENT ............................................................................................................................... 39

2.3 ALGORITHMIC ................................................................................................................................................... 39

2.4 THE ORGANIZATION CHART: ............................................................................................................................ 40

2.5 REPRESENTATION OF AN ALGORITHM................................................................................................................ 41

2.5.1 Pseudo-code: ............................................................................................................................................ 42

2.5.2 The structure of an algorithm includes: ................................................................................................... 42

2.6 CONSTANTS AND VARIABLES ............................................................................................................................ 43

2.6.1 Choice of identifiers.................................................................................................................................. 43

2.7 TYPES OF VARIABLES ........................................................................................................................................ 44

2.8 VARIABLE DECLARATION .................................................................................................................................. 44

2.9 THE ASSIGNMENT INSTRUCTION ........................................................................................................................ 45

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2.10 THE OPERATORS DEPEND ON THE TYPE OF OPERATION: ................................................................................... 46

2.11 I/O INSTRUCTIONS: READING AND WRITING .................................................................................................... 48

2.11.1 Example (reading and writing) ............................................................................................................... 48

CHAPTER 3. INDICATED VARIABLES ..................................................................................................50

3.1 TESTS: CONDITIONAL STATEMENTS ................................................................................................................... 50

3.1.1 If then ........................................................................................................................................................ 50

3.1.2 (If…Then…else) ........................................................................................................................................ 50

3.2 COMPOUND CONDITIONS ................................................................................................................................... 51

3.2.1 Nested tests ............................................................................................................................................... 53

3.3 INSTRUCTIONS CASE ......................................................................................................................................... 53

3.4 INSTRUCTIONS WITH A REPEATING/ ITERATIVE INSTRUCTIONS: LOOPS ............................................................. 54

3.4.1 Loops For ................................................................................................................................................. 55

3.4.2 Loops while............................................................................................................................................... 57

3.4.3 Loops Repeat…until… .............................................................................................................................. 58

3.4.4 Choosing a loop type ................................................................................................................................ 59

3.5 ARRAY TYPE .................................................................................................................................................... 60

3.5.1 Definition :................................................................................................................................................ 60

An array allows you to represent a set of values having common properties and all belonging to the same

type. These variables are identified by the same name but a reference number (index) for each. .................... 60

CONCLUSION ....................................................................................................................................................62