C# Operators

OPERATORS

C# Operators

Ø     C# provides a large set of operators, which are symbols that specify which operations to perform in an expression. Operations on integral types such as ==, !=, <, >, <=, >=, binary +, binary -, ^, &, |, ~, ++, --, andsizeof() 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.

^Ø    The following table lists the C# operators grouped in order of precedence. Operators within each group have equal precedence.

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 Overflow Exception 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.

DECLARATION OF PRIMITIVE DATA TYPES IN C#

Data Type

^Ø   The type of data that a variable contains is called Data Type (type). A Data Type is a classification of things that share similar type of qualities or characteristics or behavior.

^Ø   C# is strongly typed language so every variable and object must have a type.

There are two types of data type in C#

1.     primitive types (or) predefined

Ex:  byte, short, int, float, double, long ,char, bool, DateTime, string, object etc..

2.     non-primitive types (or) User Defined

Ex: class , struct , enum , interface,  delegate, array.

In C#, based on what a variable contains there is two types of built-in data type

Value types

^Ø A variable holds actual values then that type of data types are value types. These value types are stored in ―stack‖ memory and these value types are fixed in size. If you assign a value of a variable to another variable it will create two copies.

Ex: byte, short, int, float, double, long ,char, bool, DateTime.

·        Primitive data types are value types except string, object.

·        Object type is superior to all types. It can store any type or any size of data. It helps in inheritance process.

·        Struct, enum are value types.

Reference types

^Ø   A variable holds a reference to the value, then that type of data types are reference types.

^Ø   These reference types are stored in ―heap‖ memory and these types are not fixed in size.

^Ø   They are maintained in system managed heap but it also uses stack to store reference of

the heap.

^Ø Two primitive types (string and object) and non-primitive data types (class, interface & delegate) are examples of reference type.

Ex: class, interface, delegate, string, object and array

Date and Time

Date time is one of the most commonly used data type in C#.

Ex:

DateTime currenttime = DateTime.Now;//display’s current date time.

Output:

current time: 6/13/2015 4:50:45 pm

int days = DateTime.DaysInMonth(2011, 7);// it displays ―31‖.

Output:

No of days 31