- Introduction , History and features
- Data types , variable , constants , basic syntax
- Operators
- Control structures : If-else,goto,switch,break
- Control loops : while, do while, for
- Function
- Array, Matrix - 2D array
- String
- Structure, Union
- Pointer
- File handling
- programs
History :
C is a computer programming language used to do programming in operating system called UNIX. C was derived from B language . B language was adapted from BCPL(Basic Combined Programming Language) , which was developed by Martin Richards at Cambridge University.
C is an procedural oriented language developed by Dennis Ritchie in 1991 at Bell Laboratories.
Features of C :
- Procedural Oriented : In C every code or program is written with function or an procedure . That's why it is called as procedural oriented language .
- Case sensitive : C is a case sensitive language because every upper case character and lower case character have different meaning . for example upper case character A and lower case character a have different meaning .
- Middle level language : C support the high level features and also supports to low level features , hence it is an middle level language .
- Provide Translators : Everyone know that machine understands only 1 or 0 language . It is difficult to write and maintain code in machine language . Hence , c provide high level and low level language conversion. The translators are used for this conversion . Translators are the computer programs which performs this conversion and gives the machine level output properly . There are three types of translators
- Assembler
- Compiler
- Interpreter
Basic syntax of c :
//comment section - comment section
#include<stadio.h> - header files
#include<conio.h> - header files
void main() - main function()
{ - curly braces open
statements; - statements section
getch(); - linker between i/o and o/p screen
} - curly braces close
- Comment Section : This section is used to write user defined message for identification of code for user purpose only .This is not an executable part of program . It is only for user checking . Not visible in output screen .
- Header Files : This section is very important section in program . It stores all pre-define functions and statements inside it that we are going to use in program . stdio.h means Standard Input Output which stores standard library functions . conio.h means Connection Input Output which is connection between input and output .
- Main function : The main execution of program stats here . Void means null . it does not stores any type of value .
- Statements : The main program, code comes here . statements means the pre-defined loops , printf(), scanf(),etc. are going to use here .
- getch() : getch() is a function used to link input and output
Comments in C :
As we shown in our previous post we can write own comments in c program . There are two ways to write the comments in a program i.e.
- Single line comment : The single line comment is always written with // . for example i have to write my program name so , I will write //program for addition of two numbers .
- Multiline comment : The multiline comment is written with /*.......*/ For example i want to write multiline omments so I will write
program for accepting values from user*/
Data types in c :
- int : This data type is used to store integer . For example 1 2 3 . It requires 4 bytes in memory.
- char : This data type is used store characters in memory . It requires 1 byte in memory .
- float : this data type is used to store single decimal pointing integers . It requires 4 bytes in memory .
- double : This data type is used to store double decimal pointing integers . It requires 8 bytes memory .
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Variables in C :
Variable used to store any value acording to its declared data type .consider following example :int a=10;In this example , int is a data type which is used to declare or store integers through variable a . I have given variable name as a and stored 10 value ina variable i.e. variables are used to store any other value according to its data type.Rules for naming the variables :There are certain rules to give any name to an variable . It should be according to below given rules .
- Variable name should be start with character or underscore .
- cannot start variable name with number or digit .
- Variable name with upper case and lower case have different meanings . We can take upper cases as well as lower cases in variable naming.
Operators in C :-
Let's se an example ,
c=a+b
where , c=a+b is an expression
c , a, b are operands
= + are operators
Hence , operators are the symbols used to solve an expression .
An expression is an combination of operators and operands .
There are multiple types of operators as given below .
- Arithmetic Operators
- Relational Operators
- Logical Operators
- Conditional Operator
- Bitwise Operators
- Assignment Operators
- Increment and decrement operators
1. Arithmetic operators :
This operator is used to perform basic operations like addition subtraction etc.It includes
+ : performs addition- : performs subtraction/ : performs subtraction% : returns remainder after division
Example :Write Simple C program without accepting values from user.
#include<stdio.h>#include<conio.h>void main(){int a=20,b=10,c;c=a+b;printf("addition is %d",c);c=a-b;printf("Substraction is %d",c);c=a/b;printf("Division is %d",c);c=a%b;printf("remainder after substraction is 5",c);getch();}
Example : Program with accepting values from user
#include<stdio.h>#include<conio.h>void main(){int a,b,c;printf("Enter value for a : ");scanf("%d",&a);printf("Enter value for b : ");scanf("%d",&b);c=a+b;printf("addition is %d",c);c=a-b;printf("Substraction is %d",c);c=a/b;printf("Division is %d",c);c=a%b;printf("remainder after substraction is 5",c);getch();}