BitConverter Class in C#

The BitConverter class in C# provides static methods to convert base data types to byte arrays and vice versa. It handles the conversion between different data types and their byte representations, making it essential for low-level data manipulation, file I/O, and network communication.

Key Methods

Converting Data Types to Bytes

The GetBytes() method converts various data types to their byte array representation −

Example

using System;

public class Demo {
   public static void Main() {
      int number = 12345;
      double value = 3.14159;
      bool flag = true;
      
      byte[] intBytes = BitConverter.GetBytes(number);
      byte[] doubleBytes = BitConverter.GetBytes(value);
      byte[] boolBytes = BitConverter.GetBytes(flag);
      
      Console.WriteLine("Integer 12345 as bytes:");
      foreach (byte b in intBytes) {
         Console.Write(b + " ");
      }
      
      Console.WriteLine("\nDouble 3.14159 as bytes:");
      foreach (byte b in doubleBytes) {
         Console.Write(b + " ");
      }
      
      Console.WriteLine("\nBoolean true as bytes:");
      foreach (byte b in boolBytes) {
         Console.Write(b + " ");
      }
   }
}

The output of the above code is −

Integer 12345 as bytes:
57 48 0 0 
Double 3.14159 as bytes:
110 18 131 192 202 33 9 64 
Boolean true as bytes:
1 

Converting Bytes to Data Types

The ToBoolean(), ToInt32(), and similar methods convert byte arrays back to their original data types −

Syntax

public static bool ToBoolean(byte[] arr, int startIndex);
public static int ToInt32(byte[] arr, int startIndex);

Example

using System;

public class Demo {
   public static void Main() {
      byte[] arr = { 50, 100, 0, 0 };
      Console.WriteLine("Array values:");
      for (int i = 0; i < arr.Length; i++) {
         Console.Write(arr[i] + " ");
      }
      
      Console.WriteLine("\nConverted values:");
      for (int index = 0; index < arr.Length; index++) {
         bool res = BitConverter.ToBoolean(arr, index);
         Console.WriteLine("Index " + index + ": " + res);
      }
      
      int intValue = BitConverter.ToInt32(arr, 0);
      Console.WriteLine("As Int32: " + intValue);
   }
}

The output of the above code is −

Array values:
50 100 0 0 
Converted values:
Index 0: True
Index 1: True
Index 2: False
Index 3: False
As Int32: 25650

Converting to Hexadecimal String

The ToString() method converts byte arrays to hexadecimal string representations −

Example

using System;

public class Demo {
   public static void Main() {
      double d = 5.646587687;
      Console.WriteLine("Value = " + d);
      
      long res = BitConverter.DoubleToInt64Bits(d);
      Console.WriteLine("64-bit signed integer = " + res);
      
      byte[] bytes = BitConverter.GetBytes(d);
      string hexString = BitConverter.ToString(bytes);
      Console.WriteLine("Hexadecimal representation: " + hexString);
      
      string hexSubset = BitConverter.ToString(bytes, 2, 4);
      Console.WriteLine("Bytes 2-5 as hex: " + hexSubset);
   }
}

The output of the above code is −

Value = 5.646587687
64-bit signed integer = 4618043510978159912
Hexadecimal representation: 98-EE-90-1F-85-46-16-40
Bytes 2-5 as hex: 90-1F-85-46

Common Use Cases

• File I/O operations − Converting data types to bytes for binary file storage.

• Network communication − Serializing data for transmission over networks.

• Cryptography − Converting data to byte arrays for encryption algorithms.

• Memory manipulation − Low-level operations requiring byte-level access to data.

Conclusion

The BitConverter class in C# provides essential functionality for converting between data types and their byte representations. It enables efficient data serialization, file operations, and low-level memory manipulation by handling the conversion between various data types and byte arrays.