Type conversion in C ＃

C# Type conversion in

• The concept of type conversion

C# Is a strong type of language , Strict requirements for types , But under certain conditions, they can also be converted to each other , Such as the int Type data into double Type data .

C# Two conversion methods are allowed ： Implicit type conversion and display type conversion .

1. Implicit type conversion

Implicit type conversion is C# Default safe conversion , No data loss . for example , Convert from small integer type to large integer type . From a derived class to a base class .

Implicit conversion is mainly in integer 、 Conversion between floating point types , Change the data type with small storage range directly to the data type with large storage range .

Implicit numerical conversion includes the following ：

1. from sbyte Type to short,int,long,float,double or decimal type .
2. from byte Type to short,ushort,int,uint,long,ulong,float,double or decimal type
3. from short Type to int,long,float,double or decimal type
4. from ushor Type to int、uint、long、ulong、float、double or decimal type .
5. from int Type to long、ffloat、double or decimal type .
6. from uint Type to long、ulong、float、double or decimal type .
7. from long Type to float、double、 or decimal type .
8. from ulong Type to float、double or decimal type
9. from char Type to ushort、int,uint、ong、ulong、float、double or decimal type
10. from float Type to double type .

Implicit value conversion is actually the conversion from low-precision value type to high-precision value type .

2. Display type conversion

Display type conversion , Forced type conversion . Conversion requires cast operator , And the cast will cause data loss .

Forced type conversion is mainly used to convert data types with a large storage range to data types under the storage range , But data types need to be compatible .

The syntax of cast is as follows ：

Data type variable name =（ data type ） Variable name or value ;

 

• Method of data type conversion

1. Parse Method

C# Parse Method is used to character string Type conversion to Any basic type , The specific grammatical form is as follows .

Basic data type .Parse（ Value of string type ）;

The data types on the left and right sides of the equal sign are required to be compatible .

Examples are as follows ：

 

1. Convert Method

Convert Method is the most flexible method in data type conversion , It can convert the value of any data type to any data type , The premise is not to exceed the range of the specified data type .

The specific grammatical form is as follows ：

data type Variable name =convert . To data type （ Variable name ）;

here Convert . To The following data type should match the data type to the left of the equal sign .

Convert The common type conversion methods of class are shown in the following table ：

Method	explain
Convert.ToInt16()	Convert to plastic （short）
Convert.ToInt32()	Convert to plastic （int）
Convert.ToInt64()	Convert to plastic （long）
Convert.ToChar()	Convert to character （char）
Convert.ToString()	Convert to string （string）
Convert.ToDateTime()	Convert to date type （datetime）
Convert.toDouble()	Convert to double precision floating-point number （double）
Convert.ToSinge()	Convert to single precision floating point （float）

Examples are as follows ：

 

• Unpacking and packing

Packing : Convert value type to reference type .

Sealing box ： Converts a reference type to a value type .

Use the function of packing and unpacking , You can use any value of the allowed value type with object The values of type are converted to each other , Connect value types with reference types .