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Chapter 1
Introduction to C Programming
1.1 INTRODUCTION
• This book is about problem solving with the
use of computers and the C programming
language.
• how to identify problems
• Specify such problems
• Analyze them
• Design a method of solution for them
1.2 COMPUTER
FUNDAMENTALS
• A special-purpose computer is a computer
that is designed for a particular function.
• General-purpose computers.
• They are capable of storing and running
different set of instructions, accepting input
data for each set of instruction in different
forms, and producing output that satisfies
various user requirements.
Hardware
• Main memory, central processing unit, input
devices, output devices, and secondary
memory devices.
• Systems software
• Operating system : manages the overall operation
of the computer system
• Text editor : to create a text
• Preprocessor : checks the C program file for
special instructions.
• Language translator : converts a computer
program written using a high-level programming
language, to an equivalent program that is in
machine language.
• Source program : a program that is written
in a high-level language
• Object program : a program that consists of
machine language
• Interpreter : translates one instruction at a
time and immediately executes
• Compiler : translates the entire source
program
• Standard library contains object codes of
some standard programs ( called standard
library functions)
• Linker : combines the object codes of the
needed standard functions with your object
program and creates an executable machine
language program, called the load module.
The load module is saved in disk storage.
• Loader : loads the executable load module
into the main memory for execution.
• Applications software : includes programs
that are developed using systems software
in order to solve problems.
1.3 PROGRAMMING
LANGUAGES
• Special-purpose programming language is
designed for a particular class of
applications. For example, Structured Query
Language (SQL)
• General-purpose programming language
can be used to obtain solutions for many
different types of problems.
•
•
Machine Languages
Readily understood by the computer. Have
some shortcomings:
1. Difficult to learn, instruction is a binary string
of zeros and ones.
2. Even relatively simple problems require a
large number of machine language
instructions.
3. Are machine-dependent.
• Assembly Languages
• Consist of English-like abbreviations.
L
1, GROSSPAY
S
1, TAX
ST 1, NETPAY
• Assemblers, to convert assembly language
programs to machine code, have some
shortcomings :
1. Programs written in assembly languages
are lengthy.
2. Each computer type has its own assembly
language.
• High-level Languages
• English-like, single instruction can be
written to corresponds to many operations
at the machine level. For example,
netpay = grosspay – tax;
High-level programming languages have been
standardized. Quite portable.
• The Evolution of the C and C++ Programming
Languages
• Developed at Bell Laboratories in the early 1970s
as a system implementation language. C combines
the convenience of high-level programming
languages with the power of assembly languages.
• C++ programming language as an extension of the
C language.
• C++ makes object-oriented programming.
1.4 THE C PROGRAMMING
ENVIRONMENT
•
•
Language includes features that enable use
to carry out certain basic operations.
A library is a collection of routines not
part of the language. Two kinds of
libraries:
1. Standard libraries
2. Programmer-defined libraries
• Stdio library, used for interactive input and
output operations; the math library, which
contains some standard mathematical
functions
To use a standard library, say, the stdio library
#include <stdio.h>
1.5 HOW TO USE THE
COMPUTER TO RUN C
PROGRAMS
• Accessing the Computer
• Using the Editor to prepare Program and Data
Files
• Compiling, Linking, and Executing C Programs
• Correcting Compilations and Execution Errors
1.6 EXAMPLE PROGRAM 1:A
C Program that balances
Your Checkbook for Debit
Type Transactions