C# - Operators

An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. C# has rich set of built-in operators and provides the following type of operators −

  • Arithmetic Operators
  • Relational Operators
  • Logical Operators
  • Bitwise Operators
  • Assignment Operators
  • Misc Operators

This tutorial explains the arithmetic, relational, logical, bitwise, assignment, and other operators one by one.

Arithmetic Operators

Following table shows all the arithmetic operators supported by C#. Assume variable A holds 10 and variable B holds 20 then −

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Operator Description Example
+ Adds two operands A + B = 30
- Subtracts second operand from the first A - B = -10
* Multiplies both operands A * B = 200
/ Divides numerator by de-numerator B / A = 2
% Modulus Operator and remainder of after an integer division B % A = 0
++ Increment operator increases integer value by one A++ = 11
-- Decrement operator decreases integer value by one A-- = 9

Relational Operators

Following table shows all the relational operators supported by C#. Assume variable A holds 10 and variable B holds 20, then −

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Operator Description Example
== Checks if the values of two operands are equal or not, if yes then condition becomes true. (A == B) is not true.
!= Checks if the values of two operands are equal or not, if values are not equal then condition becomes true. (A != B) is true.
> Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true. (A > B) is not true.
< Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true. (A < B) is true.
>= Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true. (A >= B) is not true.
<= Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true. (A <= B) is true.

Logical Operators

Following table shows all the logical operators supported by C#. Assume variable A holds Boolean value true and variable B holds Boolean value false, then −

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Operator Description Example
&& Called Logical AND operator. If both the operands are non zero then condition becomes true. (A && B) is false.
|| Called Logical OR Operator. If any of the two operands is non zero then condition becomes true. (A || B) is true.
! Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true then Logical NOT operator will make false. !(A && B) is true.

Bitwise Operators

Bitwise operator works on bits and perform bit by bit operation. The truth tables for &, |, and ^ are as follows −

p q p & q p | q p ^ q
0 0 0 0 0
0 1 0 1 1
1 1 1 1 0
1 0 0 1 1

Assume if A = 60; and B = 13; then in the binary format they are as follows −

A = 0011 1100

B = 0000 1101

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A&B = 0000 1100

A|B = 0011 1101

A^B = 0011 0001

~A  = 1100 0011

The Bitwise operators supported by C# are listed in the following table. Assume variable A holds 60 and variable B holds 13, then −

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Operator Description Example
& Binary AND Operator copies a bit to the result if it exists in both operands. (A & B) = 12, which is 0000 1100
| Binary OR Operator copies a bit if it exists in either operand. (A | B) = 61, which is 0011 1101
^ Binary XOR Operator copies the bit if it is set in one operand but not both. (A ^ B) = 49, which is 0011 0001
~ Binary Ones Complement Operator is unary and has the effect of 'flipping' bits. (~A ) = 61, which is 1100 0011 in 2's complement due to a signed binary number.
<< Binary Left Shift Operator. The left operands value is moved left by the number of bits specified by the right operand. A << 2 = 240, which is 1111 0000
>> Binary Right Shift Operator. The left operands value is moved right by the number of bits specified by the right operand. A >> 2 = 15, which is 0000 1111

Assignment Operators

There are following assignment operators supported by C# −

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Operator Description Example
= Simple assignment operator, Assigns values from right side operands to left side operand C = A + B assigns value of A + B into C
+= Add AND assignment operator, It adds right operand to the left operand and assign the result to left operand C += A is equivalent to C = C + A
-= Subtract AND assignment operator, It subtracts right operand from the left operand and assign the result to left operand C -= A is equivalent to C = C - A
*= Multiply AND assignment operator, It multiplies right operand with the left operand and assign the result to left operand C *= A is equivalent to C = C * A
/= Divide AND assignment operator, It divides left operand with the right operand and assign the result to left operand C /= A is equivalent to C = C / A
%= Modulus AND assignment operator, It takes modulus using two operands and assign the result to left operand C %= A is equivalent to C = C % A
<<= Left shift AND assignment operator C <<= 2 is same as C = C << 2
>>= Right shift AND assignment operator C >>= 2 is same as C = C >> 2
&= Bitwise AND assignment operator C &= 2 is same as C = C & 2
^= bitwise exclusive OR and assignment operator C ^= 2 is same as C = C ^ 2
|= bitwise inclusive OR and assignment operator C |= 2 is same as C = C | 2

Miscellaneous Operators

There are few other important operators including sizeof, typeof and ? :supported by C#.

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Operator Description Example
sizeof() Returns the size of a data type. sizeof(int), returns 4.
typeof() Returns the type of a class. typeof(StreamReader);
& Returns the address of an variable. &a; returns actual address of the variable.
* Pointer to a variable. *a; creates pointer named 'a' to a variable.
? : Conditional Expression If Condition is true ? Then value X : Otherwise value Y
is Determines whether an object is of a certain type. If( Ford is Car) // checks if Ford is an object of the Car class.
as Cast without raising an exception if the cast fails. Object obj = new StringReader("Hello");

StringReader r = obj as StringReader;

Operator Precedence in C#

Operator precedence determines the grouping of terms in an expression. This affects evaluation of an expression. Certain operators have higher precedence than others; for example, the multiplication operator has higher precedence than the addition operator.

For example x = 7 + 3 * 2; here, x is assigned 13, not 20 because operator * has higher precedence than +, so the first evaluation takes place for 3*2 and then 7 is added into it.

Here, operators with the highest precedence appear at the top of the table, those with the lowest appear at the bot