Type casting is when you assign a value of one data type to another type.
In C#, there are two types of casting:
- Implicit Casting (automatically) – converting a smaller type to a larger type size and conversion from derived classes to base classes.
char-> int-> long-> float-> double
- Explicit Casting (manually) – converting a larger type to a smaller size type. It requires a cast operator.
double-> float-> long-> int-> char
Implicit casting is done automatically when smaller size type is passed to a larger size type.
Example
int myInt = 7;
double myDouble = myInt; // Automatic casting: int to double
Console.WriteLine(myInt); // Outputs 7
Console.WriteLiine(myDouble); // Outputs 7
Explicit Casting
It must be done manually by placing the type in parentheses in front of the value:
Example
double myDouble = 8.65;
int myInt = (int) myDouble; // Manual casting: double to int
Console.WriteLine(myDouble); // Outputs will be 8.65
Console.WriteLine(myInt); // Outputs will be 8
Type Conversion Methods
It is also possible to convert data types explicitly by using built- in methods, such as Convert.ToBoolean, Convert.ToDouble, Convert.ToString, Convert.ToInt32 (int) and Convert.ToInt64 (long):
Example
int myInt = 9; double myDouble = 6.25; bool myBool = true;
Console.WriteLine(Convert. ToString(myInt)); // convert int to string Console. WriteLine(Convert. ToDouble(myInt)); // convert int to double Console. WriteLine(Convert. ToInt32(myDouble));// convert double to int Console.WriteLine(Convert. ToString(myBool)); // convert bool to string
Type Conversion is also known as Type Casting.
The following example shows an explicit type conversion:
using System;
namespace TypeConversionApplication {
class ExplicitConversion {
static void Main (string [] args) {
double d = 56570.71;
int i;
// cast double to int.
I = (int) d;
Console.WriteLine(i);
Console.ReadKey();
}
}
}
When the above code is compiled and executed, it produces result 56570.
C# Type Conversion Methods
C# provides the following built-in type conversion methods −
| Sr.No. | Methods & Description |
| 1 | ToBoolean Converts a type to a Boolean value, where possible. |
| 2 | ToByte Converts a type to a byte |
| 3 | ToChar Converts a type to a single Unicode character, where possible. |
| 4 | ToDateTime Converts a type (integer or string type) to date-time structures. |
| 5 | ToDecimal Converts a floating point or integer type to a decimal type. |
| 6 | ToDouble Converts a type to a double type. |
| 7 | ToInt16 Converts a type to a 16-bit integer. |
| 8 | ToInt32 Converts a type to a 32-bit integer. |
| 10 | ToInt64 Converts a type to a 64-bit integer. |
The following example converts various value types to string type
using System;
namespace TypeConversionApplication {
class StringConversion {
static void Main(string[] args) {
int i = 70;
float f = 32.003f;
double d = 234567.765223;
bool b = true;
Console.WriteLine(i.ToString());
Console.WriteLine(f.ToString()); Console.WriteLine(d.ToString());
Console.WriteLine(b.ToString());
Console.ReadKey();
} }
}
When the above code is compiled and executed, it produces the following result −
70
32.003
234567.765223
True