C PROGRAMMING

 C language was developed in the year 1972 by Dennis Ritchie at AT&T's Bell Laboratories, USA.

C is a procedural language (executes the program step-by-step)

Basic features of C language 

• simple and efficient
• portable (it can be used in any operating system)
• extensible (can add user defined functions to it)
• modularity (not written as a paragraph but in shorter modules)
• speed (it compiles and gives output quicker)
• case sensitive ( small 'a' and capital 'A' are taken as two different variables and not as one and the same)

Structure of a C program 

• Documentation section - any comments are added after "//" and is not compiled by the compiler "/* */" is used if the comment is written in more than one line.
• Linking section - Header file that links library files should be included - #include<stdio.h>
• Definition section - Assigning a value to a variable - #define pi=3.14. It is difficult to change the value of a number everywhere in the program so this is used to conserve time.
• Global declaration section - variables are classified into local and global variables. global variables can be declared and used everywhere throughout the program whereas local variable can only be declared and used in a function.
• Main section - Program execution starts only from main section.
• Sub Program Section - Usually written under main program. 

Basic Functions of a Computer

• Accepts data 
• Processes data 
• Produces output 
• Stores result

Features of a Computer

• Speed - A computer can process data very fast at the rate of millions of instructions per second.
• High degree of accuracy - A computer can produce the accurate result even if there are lots of information to process.
• Diligence - Even after long hours of usage, a computer does not get tired or fatigued. It can perform long and complex tasks at the same rate and accuracy from the start till the end.
• Storage - Large volumes of data and information can be stored and can also be retrieved whenever required.
• Versatility - It can perform different types of tasks with the same ease.