C program

The C Language is developed for creating system applications that direct interacts to the hardware devices such as drivers, kernals etc.

printf() function

The printf() function is used for output. It prints the given statement to the console.

1.    printf("format string",argument_list);  

The format string can be %d (integer), %c (character), %s (string), %f (float) etc.

scanf() function

The scanf() function is used for input. It reads the input data from the console.

1.    scanf("format string",argument_list); 

 A variable is a name of memory location. It is used to store data. Its value can be changed and it can be reused many times.

It is a way to represent memory location through symbol so that it can be easily identified.

Let's see the syntax to declare a variable:

type variable_name;

Rules for defining variables

• A variable can have alphabets, digits and underscore.
• A variable name can start with alphabet and underscore only. It can't start with digit.
• No white space is allowed within variable name.
• A variable name must not be any reserved word or keyword e.g. int, float etc.

Types of Variables in C

There are many types of variables in c:

1. local variable
2. global variable
3. static variable
4. automatic variable
5. external variable

Types Data Types Basic Data Type int, char, float, double Derived Data Type array, pointer, structure, union Enumeration Data Type enum Void Data Type void Basic Data Types The basic data types are integer-based and floating-point based. C language supports both signed and unsigned literals. The memory size of basic data types may change according to 32 or 64 bit operating system. Let's see the basic data types. Its size is given according to 32 bit architecture. Data Types Memory Size Range char 1 byte −128 to 127 signed char 1 byte −128 to 127 unsigned char 1 byte 0 to 255 short 2 byte −32,768 to 32,767 signed short 2 byte −32,768 to 32,767 unsigned short 2 byte 0 to 65,535 int 2 byte −32,768 to 32,767 signed int 2 byte −32,768 to 32,767 unsigned int 2 byte 0 to 65,535 short int 2 byte −32,768 to 32,767 signed short int 2 byte −32,768 to 32,767 unsigned short int 2 byte 0 to 65,535 long int 4 byte -2,147,483,648 to 2,147,483,647 signed long int 4 byte -2,147,483,648 to 2,147,483,647 unsigned long int 4 byte 0 to 4,294,967,295 float 4 byte double 8 byte long double 10 byte An operator is simply a symbol that is used to perform operations. There can be many types of operations like arithmetic, logical, bitwise etc. There are following types of operators to perform different types of operations in C language. Arithmetic Operators Relational Operators Shift Operators Logical Operators Bitwise Operators Ternary or Conditional Operators Assignment Operator Misc Operator

Category	Operator	Associativity
Postfix	() [] -> . ++ - -	Left to right
Unary	+ - ! ~ ++ - - (type)* & sizeof	Right to left
Multiplicative	* / %	Left to right
Additive	+ -	Left to right
Shift	<< >>	Left to right
Relational	< <= > >=	Left to right
Equality	== !=	Left to right
Bitwise AND	&	Left to right
Bitwise XOR	^	Left to right
Bitwise OR	|	Left to right
Logical AND	&&	Left to right
Logical OR	||	Left to right
Conditional	?:	Right to left
Assignment	= += -= *= /= %=>>= <<= &= ^= |=	Right to left
Comma	,	Left to right

The if statement in C language is used to perform operation on the basis of condition. By using if-else statement, you can perform operation either condition is true or false.

There are many ways to use if statement in C language:

• If statement
• If-else statement
• Nested if

The single if statement in C language is used to execute the code if condition is true. The syntax of if statement is given below:

1. if(expression){  
2. //code to be executed  
3. }  

The if-else statement in C language is used to execute the code if condition is true or false. The syntax of if-else statement is given below:

1. if(expression){  
2. //code to be executed if condition is true  
3. }else{  
4. //code to be executed if condition is false  
5. }  

The if else-if statement is used to execute one code from multiple conditions. The syntax of if else-if statement is given below:

1. if(condition1){  
2. //code to be executed if condition1 is true  
3. }else if(condition2){  
4. //code to be executed if condition2 is true  
5. }  
6. else if(condition3){  
7. //code to be executed if condition3 is true  
8. }  
9. ...  
10. else{  
11. //code to be executed if all the conditions are false  
12. }