Represent Int32 as a Hexadecimal String in C#

To represent Int32 as a hexadecimal string in C#, you can use several methods. The most common approaches are using Convert.ToString() with base 16, or using the ToString() method with hexadecimal format specifiers.

Int32 represents a 32-bit signed integer that can hold values from -2,147,483,648 to 2,147,483,647. Converting these values to hexadecimal format is useful for debugging, display purposes, and when working with low-level operations.

Using Convert.ToString() with Base 16

The Convert.ToString() method accepts a base parameter. Setting it to 16 converts the integer to its hexadecimal representation −

using System;

class Demo {
   static void Main() {
      int val = 9898;
      Console.WriteLine("Integer: " + val);
      Console.WriteLine("Hex String: " + Convert.ToString(val, 16));
      
      // With negative numbers
      int negVal = -1234;
      Console.WriteLine("Negative Integer: " + negVal);
      Console.WriteLine("Hex String: " + Convert.ToString(negVal, 16));
   }
}

The output of the above code is −

Integer: 9898
Hex String: 26aa
Negative Integer: -1234
Hex String: fffffb2e

Using ToString() with Format Specifiers

The ToString() method with format specifiers provides more control over the output format −

using System;

class Demo {
   static void Main() {
      int val = 255;
      
      Console.WriteLine("Integer: " + val);
      Console.WriteLine("Hex (lowercase): " + val.ToString("x"));
      Console.WriteLine("Hex (uppercase): " + val.ToString("X"));
      Console.WriteLine("Hex with padding: " + val.ToString("X8"));
      Console.WriteLine("Hex with 0x prefix: 0x" + val.ToString("X"));
   }
}

The output of the above code is −

Integer: 255
Hex (lowercase): ff
Hex (uppercase): FF
Hex with padding: 000000FF
Hex with 0x prefix: 0xFF

Comparison of Methods

Working with Large Numbers

Here's an example showing hexadecimal conversion for various integer ranges −

using System;

class Demo {
   static void Main() {
      int[] values = { 0, 16, 255, 4096, int.MaxValue, int.MinValue };
      
      foreach (int val in values) {
         Console.WriteLine($"Decimal: {val,12} | Hex: {val.ToString("X8")}");
      }
   }
}

The output of the above code is −

Decimal:            0 | Hex: 00000000
Decimal:           16 | Hex: 00000010
Decimal:          255 | Hex: 000000FF
Decimal:         4096 | Hex: 00001000
Decimal:   2147483647 | Hex: 7FFFFFFF
Decimal:  -2147483648 | Hex: 80000000

Conclusion

Converting Int32 to hexadecimal strings in C# can be accomplished using Convert.ToString(val, 16) for simple conversion or ToString("X") format specifiers for more control over case and padding. Both methods handle the full range of 32-bit signed integers effectively.