Partager via

C# Operators 

  • Article

C# provides a large set of operators, which are symbols that specify which operations to perform in an expression. C# predefines the usual arithmetic and logical operators, as well as a variety of others as shown in the following table. Operations on integral types such as ==, !=, <, >, <=, >=, binary +, binary -, ^, &, |, ~, ++, --, and sizeof() are generally allowed on enumerations. In addition, many operators can be overloaded by the user, thus changing their meaning when applied to a user-defined type.

Operator category Operators

Arithmetic

+   -   *   /   %

Logical (Boolean and bitwise)

&   |   ^   !   ~   &&   ||   true   false

String concatenation

+

Increment, decrement

++   --

Shift

<<   >>

Relational

==   !=   <   >   <=   >=

Assignment

=   +=   -=   *=   /=   %=   &=   |=   ^=   <<=   >>=   ??

Member access

.

Indexing

[]

Cast

()

Conditional

?:

Delegate concatenation and removal

+   -

Object creation

new

Type information

as   is   sizeof   typeof   

Overflow exception control

checked   unchecked

Indirection and Address

*   ->   []   &

Arithmetic Overflow

The arithmetic operators (+, -, *, /) can produce results that are outside the range of possible values for the numeric type involved. You should refer to the section on a particular operator for details, but in general:

  • Integer arithmetic overflow either throws an OverflowException or discards the most significant bits of the result. Integer division by zero always throws a DivideByZeroException.

  • Floating-point arithmetic overflow or division by zero never throws an exception, because floating-point types are based on IEEE 754 and so have provisions for representing infinity and NaN (Not a Number).

  • Decimal arithmetic overflow always throws an OverflowException. Decimal division by zero always throws a DivideByZeroException.

When integer overflow occurs, what happens depends on the execution context, which can be checked or unchecked. In a checked context, an OverflowException is thrown. In an unchecked context, the most significant bits of the result are discarded and execution continues. Thus, C# gives you the choice of handling or ignoring overflow.

In addition to the arithmetic operators, integral-type to integral-type casts can cause overflow, for example, casting a long to an int, and are subject to checked or unchecked execution. However, bitwise operators and shift operators never cause overflow.

See Also

Tasks

Operator Overloading Sample

Reference

Overloadable Operators (C# Programming Guide)
C# Keywords

Concepts

C# Programming Guide

Other Resources

C# Reference
Visual C#