C - Operators

 Operators :-

An operator is a symbol which represents a particular operation that can be performed on some data.

Types of Operator:

1.   Arithmetic operators

2.   Relational operators

3.   Logical operators

4.   Assignment operators

5.   Shorthand assignment operators

6.   Conditional operators

7.   Increment & Decrement operators

8.   Bitwise operator

9.   Special operator

 1. Arithmetic Operators:

            C provides all the basic arithmetic operators. 

Operator	Meaning
+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulus Operator

 2. Relational Operators:

            Relational operators are used to compare two operands to check whether they are equal, unequal or one is greater than or less than the other.

Operator	Meaning
>	Greater than
>=	Greater than or equals to
<	Less than
<=	Less than or equals to
==	Equality test.
!=	Non-equality test.

 3. Logical Operators:

            Relational operators are used to compare two operands to check whether they are equal, unequal or one is greater than or less than the other.

Operator	Meaning
&&	Logical AND. Returns 1 if both the expressions are non-zero.
||	Logical OR. Returns 1 if either of the expression is non-zero.
!	Unary negation. It converts a non-zero operand into 0 and a zero operand into 1.

 4. Assignment Operators:

Assignment operators are used to assign the result of an expression to a variable. We use the assignment operator “=". In addition, C has a set of 'shorthand' assignment operators.

 5. Shorthand Assignment Operators:

Statement with simple assignment operator Statement with shorthand operator

Operator	Meaning
+ =	Addition
- =	Subtraction
* =	Multiplication
/ =	Division
% =	Modulus Operator

 6. Conditional Operators:

                            A ternary operator "? : " is available in C to  construct conditional expression of the form exp1 ? exp2 : exp3; where  exp1, exp2 and exp3 are expressions.

a=10;  b=15;

x=(a>b) ? a : b;

 7. Increment and Decrement Operators:

            C has two very useful operators not generally found in other languages. These are the increment and decrement operators: ++ and --.

Operator	Meaning
++	Increment
--	Decrement

8. Bitwise Operators:

            These operators are used for manipulating data at bit level. They are used for testing bits or shifting them right or left.

Operator	Meaning
&	Bitwise AND
|	Bitwise or
^	Bitwise exclusive or
<<	shift left
>>	shift right

 9. Special Operators:

Operator	Description	Example
sizeof	returns the size (length in bytes) of entity, for eg. a variable or an array, etc.	sizeof(x) will return size of the variable x
&	returns the memory address of the variable	&x will return address of the variable x
*	represents pointer to an object. The * operator returns the value stored at a memory address.	m = &x (memory address of variable x) *m will return the value stored at memory address m
. (dot) operator	used to access individual elements of a C structure or C union.	If emp is a structure with an element int age in it, then emp.age will return the value of age.
-> (arrow) operator	used to access structure or union elements using a pointer to structure or union.	If p is a pointer to the emp structure, then we can access age element using p->age
[] operator	used to access array elements using indexing	if arr is an array, then we can access its values using arr[index], where index represents the array index starting from zero
comma (,) operator:	This operator can be used to link the related expressions together.	res=(a=5, b=10, a+b); It first assigns the value 5 to a, then assigns 10 to b, and  finally assigns 15 to res.

 Precedence and Associability of Operators:

                            The precedence is used to determine how an expression involving more than one operator is evaluated. The operators at the higher level of precedence are evaluated first. The operators of the same precedence are evaluated either from left to right or from right to left, depending on the level. There are distinct levels of precedence and an operator may belong to one of the levels. This is known as also associativity property of an operator. There is list of some operators, their precedence levels and their rules of association.

Precedence	Operator	Description	Associativity
1	()	Parentheses (function call)	left-to-right
	[]	Brackets (array subscript)	left-to-right
	.	Member selection via object name	left-to-right
	->	Member selection via a pointer	left-to-right
	a++/a–	Postfix increment/decrement (a is a variable)	left-to-right
2	++a/–a	Prefix increment/decrement (a is a variable)	right-to-left
	+/-	Unary plus/minus	right-to-left
	!~	Logical negation/bitwise complement	right-to-left
	(type)	Cast (convert value to temporary value of type)	right-to-left
	*	Dereference	right-to-left
	&	Address (of operand)	right-to-left
	sizeof	Determine size in bytes on this implementation	right-to-left
3	*,/,%	Multiplication/division/modulus	left-to-right
4	+/-	Addition/subtraction	left-to-right
5	<< , >>	Bitwise shift left, Bitwise shift right	left-to-right
6	< , <=	Relational less than/less than or equal to	left-to-right
	> , >=	Relational greater than/greater than or equal to	left-to-right
7	== , !=	Relational is equal to/is not equal to	left-to-right
8	&	Bitwise AND	left-to-right
9	^	Bitwise exclusive OR	left-to-right
10	|	Bitwise inclusive OR	left-to-right
11	&&	Logical AND	left-to-right
12	||	Logical OR	left-to-right
13	?:	Ternary conditional	right-to-left
14	=	Assignment	right-to-left
	+= , -=	Addition/subtraction assignment	right-to-left
	*= , /=	Multiplication/division assignment	right-to-left
	%= , &=	Modulus/bitwise AND assignment	right-to-left
	^= , |=	Bitwise exclusive/inclusive OR assignment	right-to-left
	<>=	Bitwise shift left/right assignment	right-to-left
15	,	expression separator	left-to-right