C# | Type Casting
Prerequisite: C# Data Types
Type conversion happens when we assign the value of one data type to another. If the data types are compatible, then C# does Automatic Type Conversion. If not comparable, then they need to be converted explicitly which is known as Explicit Type conversion. For example, assigning an int value to a long variable.
Implicit Type Casting / Automatic Type Conversion
It happens when:
- The two data types are compatible.
- When we assign value of a smaller data type to a bigger data type.
For Example, in C#, the numeric data types are compatible with each other but no automatic conversion is supported from numeric type to char or boolean. Also, char and boolean are not compatible with each other. Before converting, the compiler first checks the compatibility according to the following figure and then it decides whether it is alright or there some error.
Following table shows the implicit types of conversion that is supported by C# :
|Convert from Data Type||Convert to Data Type|
|byte||short, int, long, float, double|
|short||int, long, float, double|
|int||long, float, double|
Int value 57 Long value 57 Float value 57
Explicit Type Casting
There may be compilation error when types not compatible with each other. For example, assigning double value to int data type:
prog.cs(14,21): error CS0266: Cannot implicitly convert type `double' to `int'. An explicit conversion exists (are you missing a cast?)
So, if we want to assign a value of larger data type to a smaller data type we perform explicit type casting.
- This is useful for incompatible data types where automatic conversion cannot be done.
- Here, target-type specifies the desired type to convert the specified value to.
- Sometimes, it may result into the lossy conversion.
Value of i is 765
Here due to lossy conversion, the value of i becomes 765 and there is a loss of 0.12 value.
C# provides built-in methods for Type-Conversions as follows :
|ToBoolean||It will converts a type to Boolean value|
|ToChar||It will converts a type to a character value|
|ToByte||It will converts a value to Byte Value|
|ToDecimal||It will converts a value to Decimal point value|
|ToDouble||It will converts a type to double data type|
|ToInt16||It will converts a type to 16-bit integer|
|ToInt32||It will converts a type to 32 bit integer|
|ToInt64||It will converts a type to 64 bit integer|
|ToString||It will converts a given type to string|
|ToUInt16||It will converts a type to unsigned 16 bit integer|
|ToUInt32||It will converts a type to unsigned 32 bit integer|
|ToUInt64||It will converts a type to unsigned 64 bit integer|
56.123 765 56 12 GeeksforGeeks