Distance Learning Center

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Distance Learning Center

• Lecture 3
• C Programming Language with Applications
• Melissa Lin, IT Consultant
• HenEm, Inc.
• Parkville, Missouri
• http//www.ecet.ipfw.edu/linm

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Lecture 3 Introduction to C Programming Language

• Review
• C programming Environments MS Visual Studio.NET,
  Linux, and Visual C 6.0
• Write a C program under Windows Environment
• Characteristics of C
• Basic Elements of a C Programming
• Data Types
• Example 3-1 Adding Two Integers
• Example 3-2 Running Adding Two Integers As DOS
  Command
• Reserved Keywords

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C Programming Environments

• C Programming Environments
• Linux/Unix Console Applications
  (Character-oriented) using ANSI C libraries and
  API (Application Program Interface) functions
• Windows 32 Console Applications
  (Character-oriented) using ANSI C standard
  libraries
• Windows Applications using API functions

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Writing C Programs Using MS Visual Studio .NET in
Windows Environment

• Edit a new program
• Use the mouse to click on the File menu and then
  choose
• File ? New ? Project (to create a new project)
• Edit a C program (Example - welcome.c)
• Save the program
• Save the program (from the File menu)
• File ? Save or Save As
• File Name welcome.c
• Add this program to the project

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Writing C Programs Using MS Visual Studio .NET in
Windows Environment (continue)

• Compile and build the program
• From Build menu, choose
• Build ? Build Solution
• When syntax error occurs, click on the error line
  and correct errors
• Run and test the program
• Debug ? Start without Debugging, to run program
• Or run the executable code directly under DOS
  environment

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Characteristics of C

• Basic C Characteristics
• A General Purpose Programming Language
• Highly Portable
• Generate Fast Codes
• Small Size Language
• Relative Low-level
• Memory access ( address), register
• C Standard library functions

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Characteristics of C (continue)

• Modern Control Structures
• - if, if-else, for, while, do-while, switch,
  case,
• Bit-wise operations
• (AND)
• (OR)
• (NOT)
• (EXOR)
• ltlt (Left Shift)
• gtgt (Right Shift)
• Logical operations
• Logical AND
• Logical OR

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Characteristics of C (continue)

• Pointer Implementation
• Data Types
• char (signed or unsigned, small integer)
• int (signed or unsigned, short 16-bit, long)
• float and double
• Arrays char arrays (strings), int arrays, float
  arrays, etc
• Pointers char, int, float, struct, functions,
  pointers
• struct (record)
• bit-field struct and union

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Commonly used Terms

• Statements
• Describe some program actions
• Example printf(Welcome to C \n)
• Execute for its effect
• Type of Statements
• Declaration statement
• Expression statement (arithmetic operations,
  assignment, function calls)
• Compound statements (a series of statement to be
  treated as a single statement)
• Selection statement (if, else, switch)
• Iteration statement (while, do, for)
• Jump statement (break, continue, return)

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C Identifiers (names)

• A sequence of letters, digits, underscores
• Must begin with a letter (not a digit)
• Cannot be a key word
• Can be any length, but only the first 31
  characters are recognized
• Case sensitive (lower and upper -case letters are
  treated differently)
• Examples
• x x1 name
• Number accountNumber value

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Escape Sequence

• The backslash (\) is called an escape character.
  When encountering a backslash in a string, the
  complier looks ahead for the next character and
  combines it with the backslash to form an escape
  sequence.
• Example Printf(Welcome to C \n)
• Escape Sequence Description
• \n New Line
• \t Horizontal Tab
• \a Alert Sound the system bell
• \\ Insert a backslash in a string
• \ Insert a double quote in a string
• \000 octal number
• \xhh hexadecimal number

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lvalues rvalues

• A lvalue is an expression referring to an object
  that may be altered
• An object is a region of memory that can be
  examined and stored into
• lvalues means left values, variable names are
  said to be lvalues because they can be used on
  the left side of an assignment operator
• rvalues means right values, constants are said to
  be rvalues because they can be used only on the
  right side of an assignment operator

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Basic Elements of C

• Basic Elements include
• Character set
• Constants
• Variables
• Data types
• Reserved Words
• Expressions
• Preprocessor
• Functions
• Operators

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Basic Elements of C (continue)

• Character set
• A, Z, a, . z, 0, 1, 2, , 9, and special
  symbols
• Constants
• Integer constants
• Octal 0, 1, 2, 3, 4, 5, 6, 7
• Decimal 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
• hexadecimal 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b,
  c, d, e, f or (A, B, C, D, E, F)
• Example decimal 31 can be written as octal 037,
  or as hexadecimal 0x1f

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Basic Elements of C (continue)

• ASCII character constants
• a, A, .. z, Z, 0, 1, 2, 9
• String constants
• W or The C programming Language
• Floating-point number constants
• 123.5 0.0 0.1E-6
• Variables
• int, long, char, float, double, array, etc.
• Data types
• char, int, long, float, constant, etc.

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Data Types

• Integer types include char, int, short, and
  long
• Type Description
• char byte (8-bit) or 32-bit integer (-128 ..
  0..127)
• int integer (32-bit) integer 16-bit (-32,768
  .. 0 .. 32,767)
• short 16-bit integer signed
• long long integer (double size of integer)
• unsigned char
• unsigned int
• unsigned short
• unsigned long

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Data Types (continue)

• Floating-point types represent floating-point
  (real) numbers
• Type Description
• float single precision floating point number
• double double precision floating point number
• long double
• Constants types includes literal constants,
  Symbolic constants
• Type Description
• literal actual number or characters
• Symbolic named associated with literal case
  sensitive

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Example 3-1 Adding Two Integers

• Adding two integers
• Using scanf() function to obtain two integer
  typed numbers entered by a user at the keyboard
• Calculating the sum of both values
• Printing the result using printf() function

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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
Solution Explorer
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-1 Adding Two Integers (cont.)
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Example 3-2 Running Compiled Adding Two Integers
Program as DOS Command
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Example 3-2 Running Compiled Adding Two Integers
Program as DOS Command
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Example 3-2 Running Compiled Adding Two Integers
Program as DOS Command
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Reserved Keywords

• Cs Keywords
• auto double int struct
• break else long switch
• case enum register typedef
• char extern return union
• const float short unsigned
• continue for signed void
• default goto sizeof volatile
• do if static while

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Reserved Keywords for Visibility and Life Time
Controls

• Auto -- dynamic, local to a program or function
  module short term variables on stack memory
• Extern -- to be available at the program linking
  time
• Static -- long term variables on data memory
• Volatile -- advise an optimizing compiler that
  the variable is important and do not attempt to
  remove it if it not used
• Const -- longest life, cannot be altered after
  the definition read only

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Expressions

• Expression is a statement or a part of a
  statement.
• Simple expression
• -- x y
• Simple decision making
• -- If else
• Multiple decision making
• -- switch
• -- default
• -- case
• -- break

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Iteration Control

• Iteration uses a repetition structure
• Examples
• for - for loop iteration
• while - while loop
• do/while - do/while
• continue - exit the inner loop and restart
  from the outer loop
• break - exit a block

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Preprocessors

• Preprocessing occurs before a program is
  compiled. Its actions are the inclusion of other
  files, definition of symbolic constants and
  macros, conditional compilation of program code
  and conditional execution of preprocessor
  directives.
• include preprocessor directive
• define preprocessor directive
• Symbolic constants
• Macros
• Conditional compilation
• error and program preprocessor directives
• and Operators
• Line Numbers
• Predefined Symbolic Constants
• Assertions

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Functions

• Functions allow the programmer to modularize a
  program. All variables defined in function
  definitions are local variables they are known
  only in the function in which they are defined.
• return -- return from a function and go back to
  caller
• void -- no values associated with parameter or
  arguments in a function
• A list of parameters as local variables
• Examples
• int main()
• printf(Welcome to C \n)
• scanf(Enter Input d , intetger1)

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Summary

• Review
• C programming Environments
• Write C programs under Windows Environment
• Characteristics of C
• Basic Elements of the C Programming
• Data Types
• Reserved Keywords
• Write a Simple Addition Program in C
• Next
• Constants and Variables
• Operators of the C Language

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Question?

• Answers
• linm_at_ipfw.edu