Operators

Operator: (LARACIBUS)


     Logical operators: (B)

     Arithmetic operators: (B)

     Relational operators: (B)

     Assignment operators: (B)

     Conditional operators: (T)

     Increment and decrement operators: (U)

     Bitwise operators: (B)

     Special operators:

      Unary(U): operator has only one operand.

           Syntax:
                  <operator> <operand>;
                                    or
                  <operand> <operator>;

       Binary(B): operator has two operands.

            Syntax:
                   <operand1> operator <operand2>;

       Ternary(T): operator has three operands.

            Syntax:
                   <Variable> = <(condition)>? <true part of condition> :
                   <false part of condition>;

                             

printf & scanf Statement

printf : It is use to print any message or value of any variable.

     Syntax:

        printf("message");

              or

        printf("message <control_string>",variable);

  Where.....

     <control_string>

     Message: Message that you want to print on console.

     Variable: Variable name which value you want to print.

 

scanf : It is use to read value of variable from user(console).

     Syntax:

        scanf("message <control_string>”,&variable1,&variable2,...&variable);

how to get value from user or console and print it on console?

Scan and Print value of Variable

File Name: "file_name.c"

Code:

void main()
{
int a;
clrscr();
printf("enter a value of a:");
scanf("%d",&a); //scan the value of a from console
printf("value of a =%d",a);
}

Output:

 

Variable & Data Type

Variable: A variable is a data name that may be used to store a data value.

     Primary data_type:

          Syntax:

               <data_type> <variable _name>; //declaration

                                                 or

               <data_type> <variable_name> = <Value>; //declaration & assignment

     User define data_type:

          typedef: “type definition” allows to users to define an identifier that would represent an existing data_type.

          Syntax:

                typedef <data_type> <identifier>;

          enum: “enumerated” data_type allows declaring variables that can have one of the values enclosed within the braces (known as “enumeration”).        

          Syntax:

                enum <identifier> {Value1, Value2, Value3, ...ValueN};

     <data_type>:

     <variable_name>:

• Variable name must be beginning with the letter.Some systems permit underscore (“_”) as the first character.
• ANSI standard recognize a length of 31 characters. But length should not be more than 8 characters, since only first 8 characters are treated as significant by compiler (C99 supports 63 characters).
• Uppercase and lowercase are distinguished.
• Variable name should not be a “keyword”
• “White space” is not allowed.

Simple program

printf Statement

File Name:"file_name.c"

Code:

void main()
{
printf("Hello !!!");
}

Output:

 

Basic Structure of c program

Documentation Section: - It includes a comment statement that gives detail information about program.

Linking Section: - It provide introduction to compiler about linked functions and included library files (header files).

Definition Section: - Define all symbolic constant.

Global Declaration Section: - Variables that are declared globally which are available in all function in program.

Main () function Section: - Every c program has only one main function in which program code is written and it content two parts.

Note: By default return type of main function is “int”.

Declaration Part: - All variables must be declared before it used or executable part.

Execution part: - Executable code should be written in this section. There should be at least one statement in this part which contains instructions to perform given task.

Note:

• The declaration and executable part must be written in between the opening and closing braces.

• All statements in the declaration part must end with the semicolon.

• C is a case sensitive programming language. It means in C printf and Printf will have different meanings.

• C has a free-form line structure.

• Multiple statements can be one the same line.

• White Spaces (ie tab space and space bar ) are ignored.

Sub program Section: - It contents all user define functions which are called in main function.

 

Introduction to C language

C is a general-purpose high level language that was originally developed by Dennis Ritchie for the Unix operating system. It was first implemented on the Digital Equipment Corporation PDP-11 computer in 1972.

• Simple and Easy to learn
• Structured language
• It procedure oriented programing language
• It can handle low-level activities.
• It can be compiled on a different type of computers.
• It is platform depended language.

Facts about C

• UNIX operating system was written in C language
• C is a modified language of B which was introduced around 1970
• The language was formalized in 1988 by the American National Standard Institue (ANSI).
• Unix Os was almost written in C by 1973.
• Nowadays C is widely used System Programming Language.
• Most of the state of the art software have been implemented using C like google,adobe system,mozila,etc..

Why to use C ?

Applications of C Language:
• Operating Systems
• Text Editors
• Language Compilers
• Print Spoilers
• Language Interpreters
• Network Drivers
• Modern Programs
• Assemblers
• Utilities
• Data Bases

Program File

All the C programs are written into text files with extension ".c" for example "file_name.c". You can use "vi" or “turbo C” editor to write your C program into a file.

Compilers

When you write any program in C language then to run that program you need to compile that program using a C Compiler which converts your program into a language understandable by a computer. This is called machine language (ie. binary format). So before proceeding, make sure you have C Compiler available at your computer. It comes alongwith all flavors of Unix and Linux.

Click this link and download turbo C

http://turbo-c.soft32.com/download/file/id/471688/?