Introduction to C language

• C is a programming language developed at AT & T's Bell Laboratories of USA in 1972.
• It was designed & written by Dennis Ritchie.

Computer program: 
A computer program is a set of instructions given to the computer to solve a problem.


Computer programming Language:
It is a language in which a computer program is written. 
eg. C, C++, Java.

Compiler:
A compiler is a ready made computer program written in a computer programming language into the language that computer understands.
i.e. ON (1) and OFF  (0)

Turbo C Compiler:
TC is also called an Integrated Development Environment (IDE). Since TC compiler not only converts a program written in C language into MLL (Machine level language) but also provides an environment to :

• Create new files
• Open existing files
• Save the files
• Make changes in files.  

Steps to start TC:

1. Start your computer
2. Switch from windows OS to DOS (Disk Operating System).
3. Change to the TC directory. CD/TC/BIN
4. Stary TC. TC
5. Maximize the window. Alt + enter.

steps to exit from TC:

1. From the menu, select File -> Quit
2. To exit from window type 'exit'.

    

Steps in learning English language:-

Alphabets -> words -> sentences -> paragraphs

Steps in learning C language:-

Alphabets         Constants         

Digits          ->  Variables   -> Instructions -> Program

Special               Keywords

Symbols

C Constants:-

1. primary constants:
1. Integer constants
2. Real Constant
3. Character constants
2. Secondary Constants:
1. Arrays
2. pointer
3. structure
4. union
5. Enum

* Integer constants-

• It must not have a decimal point.
• It may be positive or negative.
• eg. 426, 782, -8000,-7605.

* Real constants-

• Real constants are often called floating point constants.
• It must have a decimal point.
• It may be positive or negative.
• Eg. +325.34, 426.0, -48.5792
• Real constants can be expressed in two forms i.e. fractional or exponential.

* Exponential form-

• Real constants is expressed in two parts.
• The part appearing before e is called mantissa, whereas the part following e is called exponent.
• Thus 0.000342 can be expressed in exponential form as 3.24 e-4.
• Eg. +3.2 e-5
• we may use e or E.

* Character constants-

• Eg. 'A','I','5','='
• The inverted commas should point towards left.