Programming and problem solving with ADA 95

951 Pages·2000·5.17 MB·English

by  Nell B. Dale

Programming
and
Problem Solving
with Ada 95
Second Edition

Programming
and
Problem Solving
with Ada 95
Second Edition
Nell Dale
University of Texas, Austin
Chip Weems
University of Massachusetts, Amherst
John McCormick
University of Northern Iowa, Cedar Falls
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Library of Congress Cataloging-in-Publication Data
Dale, Nell B.
Programming and problem solving with ADA / Nell Dale, Chip Weems, John McCormick.—2nd ed.
p. cm.
Includes index.
ISBN: 0-7637-0792-9
1. Ada (Computer program language) I. Weems, Chip II. McCormick, John (John W.) III. Title.
QA76.73.A35 D36 2000
005.13'3—dc21 99-049488
Printed in the United States of America
04 03 02 01 00 10 9 8 7 6 5 4 3 2 1
This book is dedicated to you, and to all of our students, for whom it was begun and without
whom it could never have been completed.
N. D.
C. W.
J. M.
To Naomi, wife and best friend.
J. M.

Contents
PREFACE xxi
ACKNOWLEDGMENTS xxix
1
OVERVIEW OF PROGRAMMING AND PROBLEM SOLVING 1
Overview of Programming 2
What Is Programming? 2
What Is a Computer? 3
Background Information: Mainframes, Micros, and Minis 9
How Do We Write a Program? 13
Theoretical Foundations: Data Representation 18
What Is a Programming Language? 19
Problem-Solving Techniques 23
Ask Questions 25
Look for Things That Are Familiar 25
Solve by Analogy 26
Means-Ends Analysis 27
Divide and Conquer 27
The Building-Block Approach 28
Merging Solutions 29
How to Start 29
Algorithmic Problem Solving 30
Software Engineering 30
Programming at Many Scales 31
viii Contents
The Ada Programming Language 33
Background Information: The Origins of Ada 35
Problem-Solving Case Study: A Company Payroll 37
Summary 42
Quick Check 43
Answers 44
Exam Preparation Exercises 44
Programming Warm-up Exercises 46
2
ADA SYNTAX, SEMANTICS, AND THE PROGRAM
DEVELOPMENT PROCESS 47
The Elements of Ada Programs 48
Syntax and Semantics 48
Identifiers 51
Matters of Style: Using Meaningful, Readable Identifiers 53
Data Types 53
Background Information: Data Storage 54
Declarations 57
Software Engineering Tip: Using Constants 60
Executable Statements 62
Output: Packages and Procedures 68
Commenting a Program 71
Background Information: Ada Lovelace 72
Program Construction 74
Program Entry, Correction, and Execution 76
Entering a Program 76
Compiling and Running a Program 77
Debugging 78
Software Engineering Tip: Understanding Before Changing 79
More About Expressions 79
Precedence Rules 80
Static Expressions 83
Type Conversions 83
Background Information: Strongly Typed Languages 84
Formatting Output 85
Line Spaces and Blanks 85
Contents ix
Integer Numbers 86
Float Numbers 87
Matters of Style: Program Layout 89
The Use Package Clause 90
Problem-Solving Case Study: Mileage 94
Problem-Solving Case Study: Filling Down Comforters 97
Testing and Debugging 101
Testing and Debugging Hints 102
Summary 102
Quick Check 103
Answers 105
Exam Preparation Exercises 106
Programming Warm-up Exercises 111
Programming Problems 114
3
INPUT AND DESIGN METHODOLOGY 117
Getting Data into Programs 118
Input of Numeric Data 118
Input of String Data 121
Theoretical Foundations: More About Procedures and Parameters 124
String Slices 125
Input of Mixed Data Types 129
File Input/Output 138
Background Information: Charles Babbage 143
Programming Methodology 145
Top-Down Design 145
Object-Oriented Design 152
Software Engineering Tip: Documentation 153
Problem-Solving Case Study: Mixing Proportions 154
Testing and Debugging 159
Testing and Debugging Hints 160
Summary 161
Quick Check 162
Answers 162
Exam Preparation Exercises 162
Programming Warm-up Exercises 164
Programming Problems 166