C Programming.
Operators in C tutorials

The variables, which are declared and defined, are the operands which are operated upon by the operators.

Operators specify what operations are to be performed on the operands.

Some operators require two operands, while few operators require only one operand.

C includes many operators, which fall into different categories as follows.

ARITHMETIC OPERATORS

UNARY OPERATORS

RELATIONAL AND LOGICAL OPERATORS

ASSIGNMENT OPERATORS

CONDITIONAL OPERATORS
1) ARITHMETIC OPERATORS
There are 5 arithmetic operators in C.
Operator Used for
+ Addition
 Subtraction
* Multiplication
/ Division
% Remainder after integer division
Note: There is no exponentiation operator in C. However you can use library function pow() to carry out exponentiation. pow() function will require <math.h> library file.
Expression Valid / Invalid result result type
i + f valid 17.5 float
i + i valid 20 integer
i + c valid 75 integer ( 10 + ASCII value 65)
(i+c) – (2*f/5) valid 72.000000 float
Note that above expression will be valid, however
If you try to perform ( i + f ) % 3; will be invalid, because result of ( i + f ) will be floating point, and modulus will not work on floating point.
(data type) expression
We need to perform type cast, this is called a type cast.
( i + f ) % 3 in above example is invalid due to floating point result. To get answer we need to perform type cast as follow.
( (int) ( i + f )) % 3 this expression type cast the floating point result to int and then modulus will work on it. This is valid expression.
2) Unary Operators

As operators work on single operands, they are called unary operators.

Most common unary operator is unary minus, where a minus sign precedes a numeric variable or expression.

Unary minus operator is different from arithmetic minus (Subtraction). Arithmetic subtraction or minus operator requires two operands.
For example
150
 ( a + b )
 4 * ( 2 + 3 )
Other Unary Operator
a) Increment operator ++. The increment operator ++adds 1 to operand.
b) Decrement operator  . The decrement operator  subtracts 1 to operand.
Both Increment and Decrement operator can be used in two different ways.
Pre : If unary operator precedes the operand for example (++ operand or   operand), then value of operand will be increased / decreased by one, before it is utilized within program.
Post: If unary operator follows the operand for example (operand++ or operand  ), then value of operand will be increased / decreased by one, after the execution of statement within program.
3) Relational and Logical Operator

Relational operators are used for comparison and checking.

These are called relational or conditional or logical or Boolean operators.

Result is Boolean and it operates on all simple types of operand such as int, float or char.

These operators are used to check condition or control statements.
Operator 
Meaning 
< 
Less than 
> 
Greater than 
= = 
Equal to 
< = 
Less than or Equal to 
> = 
Greater than or Equal to 
! = 
Not equal to 
4) Assingment operator

Simple assignment operators: The equal (=) sign is used for assigning a value to variable. The lefthand side has to be a variable and righthand side of equal sign has to be value of variable.
for e.g
a = 5; // this statement will assign 5 to variable a.
b = 2 + 10; // this statement will solve right hand side equation and assign 12 to b.
x = y = z = 20; // this this example of multiple assignment, it will assign 20 to x, y and z.

Shorthand assignment operator: The plus equal (+=), minus equal (=), multiply equal (*=), divide equal (/=), modulo equal (%=), the use of shorthand assignment operator has three advantages listed below:

What appears on the lefthand side need not be repeated and therefore it becomes easier to write. The statement is more concise and easier to read.
You can also use shorthand assignment operator as follow.Assume A = 5 and B=2 then check following. 

Operator 
Regular Expression 
Shorthand assignment,Expression can be written as 
Result of A 
+ = 
A = A + B ; 
A += B; 
7 
 = 
A = A – B ; 
A  = B; 
3 
* = 
A = A * B ; 
A * = B; 
10 
/ = 
A = A / B ; 
A / = B; 
2 
% = 
A = A % B ; 
A % = B; 
1 
5) Logical Operators

The logical operator && logcal AND,  meaning OR, ! meaning NOT.

The logical operator && and  are used when we want to test more than one condition and makes decisions.

When result of both operands are true (T), && (AND) operators gives true result, otherwise it gives false.

When result of any operands is true (T),  (OR) operators gives true result, otherwise it gives false.

( ! ) NOT operators reverse Boolean result.
Truth table for each logical operators are below:
Result of ACondition 
Result of B Condition 
AND conditionA && B 
OR conditionA  B 
Not Condition! A 
T 
T 
T 
T 
F 
T 
F 
F 
T 
F 
F 
T 
F 
T 
T 
F 
F 
F 
F 
T 