An Introduction to C Programming Language

An Introduction to C Programming Language

• 1.
  LECTURE 2: An Introductionto C Programming Language
• 2.
  Why Use CProgramming Language? 1. C is a powerful and flexible language. 2. It’s a fundamental popular language preferred by most programmers. 3. C is portable, meaning a C program written in one computer system can be compiled and run on another system. 4. Supports Modular Programming Development Using Functions. 5. Supports Software Reusability.
• 3.
  C Programming DevelopmentLife Cycle. (PDLC) 1. Create Source Code: Series of statements or commands that instruct the computer to perform a desired task. 2. Using In- Built Editors: Enter the source code in to the compiler, e.g. gcc linux editor 3. Compile the Source Code. 4. Linking to create an executable file. 5. Complete the development life cycle.
• 4.
  Diagrammatic Representation ofthe PDLC
• 5.
  The Structure ofa C Program 1: #include <stdio.h> // header file 2: main() // beginning of program body 3: { //beginning of program body 4: printf("Hello, World!n"); //Displays Output 5: return 0; // terminate the program normally, return value 0 to the operating system. 6: } // symbolizes end of program body
• 6.
  Components of aC Program • Header files: #include<stdio.h>, the #include instructs the compiler to add contents of the include file to your program during compilation. • main(): beginning of program body. • Variable definition: A variable is a name assigned to a data storage location. • Function Prototype*: {Refer to Functions Later} • Program Statements or lines of code: (as above) • printf: displays information on the screen output
• 7.
  Cont’d… • scanf: readsdata from keyboard. • return: abort program normally and return control to the operating system. • comments: /*……*/ or // • braces: enclose the program body symbolizing the beginning and end of program body {…}
• 8.
  Variables & Constants •Storing data in C programs we use variables or constants. • Variables: A named data storage location in your computers memory e.g. a, cal_num. Not acceptable variables #a, cal num etc. • Reserved words (Keywords): should never be used as variables such as the data types, functions. • Constants: have defined values e.g. PI = 3.142
• 9.
  C Fundamental NumericData Types Data Type Keyword* (C Format !) Bytes Required Range* Character Char 1 -128 to 127 Integer Int 2 -32768 to 32767 Short integer short int 2 -32768 to 32767 Long integer long int 4 -2,147,483,648 to 2,147,438,647 Unsigned character Unsigned char 1 0 to 255 Unsigned integer Unsigned int 2 0 to 65535 Unsigned short integer Unsigned short int 2 0 to 65535 Unsigned long integer Unsigned long int 4 0 to 4,294,967,295 Single-precision floating-point float 4 1.2E-38 to 3.4E381 Double-precision floating-point double 8 2.2E-308 to 1.8E3082
• 10.
  Variable Declaration • inta; • float cal_num; • Other Keywords (Read!): enum, typedef, constants, symbolic constants, literal constants with a const keyword Note: • #define PI 3.31412 and int a = 22.4
• 11.
  ASSIGNMENT!!! In groups of10, prepare short presentations slides (5) to demonstrate how we use the following compiler to edit, debug and compile computer programs : 1. BorlandC 4.5 Compiler or Higher Version {5 Marks} 2. Linux Compiler {7 Marks} Requirements: {Demo [Slide # 5]: Structure of a Program}  Members will be chosen randomly to demonstrate on how these compilers work on behalf of the entire group.  On presenting you must present list of group members.  Use Microsoft Slides for Presentation/Demo Purposes.  Members from @ group will be selected randomly to represent the rest of the members.  Deadline: 6th October 2013
• 12.
  Readings ! • TheFundamental Operators in C Programming • C Expressions {Simple and Complex} • Statements in C {Simple and Compound} • Reserved (Key)Words in C Programming Language • Order of Precedence in C complex expressions • Define Variables, Declaration of Variables • Assigning a value to a Variable • How do Input and Output values in the Program? {which functions are used & how?}