Operators in C Language

Operators are used to perform some operations in C Programming Language and can be categorized in two ways-

1. Based on Operands
2. Based on functionality

1. Based on Operands

1. Unary Operators

Operators which take only one operand or perform operations on single operands are known as Unary Operators. Example: ++,--,- etc are unary operators.

2. Binary Operators 

Operators which take two operands or perform operations on two operands are knows as Binary Operators. Example: +, *, /, % etc.

3. Ternary Operators

Operators which take three operands or perform operations on three operands are known as Ternary Operators. Example: Conditional Operator(? :).

2. Based on Functionality

Operators in C Language

1. Arithmetic Operators

Operators are used to perform arithmetic operations are known as Arithmetic Operators. Example: +,-,*,/ and %.

Operator Symbol	Meaning	Example (X=9, Y=2)	Result
+	Addition	X+Y	11
-	Subtraction	X-Y	7
*	Multiplication	X*Y	18
/	Division	X/Y	4
%	Modulus or Remainder	X%Y	1

**Point to Remember- the division result of integer values is always an integer value.

2. Relational Operators  

Operators are used to perform Relational operations are known as Relational Operators. Example: <,>,<=,>=,== and !=. The result of Relational Operator is always either True or False.

Operator Symbol	Meaning	Example (X=9, Y=2)	Result
= =	Equal to	X= =Y	False
! =	Not Equal to	X! = Y	True
<	Less Than	X<Y	False
>	Greater Than	X>Y	True
< =	Less Than or Equal to	X < = Y	False
> =	Greater Than or Equal to	X > = Y	True

3. Logical Operators

Operators are used to perform Logical Operations are known as Logical Operators. Example: ||,&&,!.

Logical AND Table			Logical OR Table			Logical NOT Table
X	Y	X && Y	X	Y	X || Y	X	!X
True	True	True	True	True	True	True	False
True	False	False	True	False	True
False	True	False	False	True	True	False	True
False	False	False	False	False	False

Operator Symbol	Meaning	Example (X=9, Y=2)	Result
&&	Logical AND	X > 5 && Y >5	False
||	Logical OR	X > 5 || Y > 5	True
!	Logical NOT	!(X > 5 || Y > 5)	False

4. Assignment Operators

Operators are used to perform Assignment operations are known as Assignment Operators. Example: =,+=,-=,*=,/= and %=.

Assignment Operators +=, -=, *=, /= and %= are also known as short hand operators in C Programming. 

let us understand why these are called short hand operators-

a=a+5 is similar to a+=5 according to result but wait here += is single operator according to compiler hence a+=5 is faster than a=a+5 and that's why these are called short hand operators. similarly -=, /=,*= and %=.

Operator Symbol	Meaning	Example (X=9, Y=2)	Result
=	Assignment	Z=X	value of X is assigned to Z
+=	addition before assignment	X+=Y	X is 11 similar to X=X+Y
-=	subtraction before assignment	X-=Y	X is 7  similar to X=X-Y
*=	Multiply before assignment	X*=Y	X is 18 similar to X=X*Y
/=	Divide before assignment	X/=Y	X is 4 similar to X=X/Y
%=	Modulus before assignment	X%=Y	X is 1 similar to X=X%Y

5. Increment and Decrement Operators(Unary Operators)

Operators are used to perform Increment and Decrement operations are known as Increment and Decrement Operators. Example: ++, --.

These operators are used in pre and post order and hence there will be of two meanings.

Let us understand the difference between pre and post increment or decrement-

assume we have two variables a and b. variable a having value 5 and we have to assign value with increment operator or decrement operator like-

b=++a;            //assume a=5

//here ++ is used before variable a hence pre increment is used. by this processor, read a than increment its value by 1 and than assign to variable b. after operation a=6 and b=6.

b=a++;          //assume a=5

//here ++ is used after variable a hence post increment is used. By this processor read a, assign its value to b and than it increment the value by 1.  After operation a=6 and b=5.

Similar with pre and post decrement also

b=--a;   //assume a=5 and after operation a=4 and b=4.

b=a--;   // assume a=5 and after operation a=4 and b=5.

Operator Symbol	Meaning	Example (X=9)	Result
++	Increment	++X (pre increment) X++ (post increment)	X is 10
--	Decrement	--X (pre decrement) X-- (post decrement)	X is 8

5. Bitwise Operators

Operators are used to perform operations on Bits are known as Bitwise Operators. Example: |,&,~,<<,>>

Operator Symbol	Meaning	Example (X=6, Y=3)	Result
&	Bitwise AND	X&Y	2
|	Bitwise OR	X|Y	7
~	Bitwise NOT	~X	-7
>>	Bitwise Right Shift	Y>>1	1
<<	Bitwise Left Shift	Y<<1	6

6. Conditional Operators

Operators are used to perform operations on Conditional basis are known as Conditional Operators and also known as Ternary Operator. Example: ? :

Operator Symbol	Meaning	Example (X=9, Y=2)	Result
? :	Conditional Operator	(X>9)?X=5:Y=5	5 is assigned to Y

7. Special Operators

Operators are used to perform some special operations are known as Special Operators. Example: sizeof(), pointer operator(*), Address Operator(&) and Comma operator(,).

Operator Symbol	Explaination
sizeof()	sizeof() is not a function it is an operator which is used to return an integer value of allocation size of a variable. Example:  int a; //here a is an integer variable float b; //here b is a float variable sizeof(a) //it gives 2 because a is integer and its allocation size is 2 byte. sizeof(b) // it gives 4 because b is float variable and its allocation size is 4 byte.
*	pointer operator is used to declare pointer as well as to fetch the value from an address which  is pointed by pointer. Example: int a=5;  //a variable having value 5 int *b; // here * is used to declare pointer variable b=&a; //pointing to location a printf("%d", *b); //here * is used to fetch value from address pointed by pointer b.
&	Address operator is used to take an address of a variable. Example: int *b=&a;// here address of a is assigned to pointer b.
->	arrow operator is used in a program when the member of structure or union are fetched by using pointer. We will discuss it in Structure or Union section.
,	comma operator is used to make different operation side by side in sequence. Example: c=5,b=c,a=b; in this 5 is assigned to c first than c is assigned to b and than finally b is assigned to a.