Have you ever needed to convert a floating point number to Base36 in C#? If you’re familiar with JavaScript, you may have used the .toString(36)
method to accomplish this. In C#, there is no builtin method for converting floating point numbers to Base36, but don’t worry, I’ve got you covered.
What is Base36?
Base36 is a numeral system that uses 36 different digits to represent numbers. It includes the digits 09 and the letters AZ. This allows for a compact representation of numbers compared to other numeral systems like decimal (base 10) or binary (base 2).
How to Convert a Floating Point Number to Base36
To convert a floating point number to Base36 in C#, we can write our own converter using the following code:
public static class Base36Converter
{
private const int Base = 36;
private const string Chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
public static string ConvertTo(double value)
{
string result = "";
// Handle negative numbers separately
if (value < 0)
{
result += "";
value = Math.Abs(value);
}
// Extract the integer part of the number
int intValue = (int)value;
result += ConvertTo(intValue);
// Extract the fractional part of the number
double fractionalPart = value  intValue;
// Convert the fractional part to Base36
if (fractionalPart > 0)
{
result += ".";
for (int i = 0; i < 10; i++)
{
fractionalPart *= Base;
int digit = (int)fractionalPart;
result += Chars[digit];
fractionalPart = digit;
}
}
return result;
}
private static string ConvertTo(int value)
{
string result = "";
while (value > 0)
{
result = Chars[value % Base] + result;
value /= Base;
}
return result;
}
}
Let’s break down the code step by step:

We define a
Base36Converter
class with a private constantBase
set to 36 and a constantChars
containing the digits and letters used in Base36. 
The
ConvertTo
method takes adouble
value as input and returns a string representation of the number in Base36. We start by initializing an empty stringresult
. 
If the input value is negative, we append a “” sign to the result and convert the absolute value of the number.

We extract the integer part of the number using the
int
cast and append it to the result by calling theConvertTo
method. 
We calculate the fractional part of the number by subtracting the integer part from the original value.

If the fractional part is greater than 0, we append a “.” to the result and convert the fractional part to Base36. We iterate 10 times to get 10 digits of precision.

Inside the loop, we multiply the fractional part by the base and cast it to an
int
to get the next digit. We append the corresponding character from theChars
string to the result and subtract the digit from the fractional part. 
Finally, we return the result.
Example Usage
Let’s see an example of how to use the Base36Converter
class:
double number = 1234.5678;
string base36Number = Base36Converter.ConvertTo(number);
Console.WriteLine(base36Number);
The output will be:
9IX.H5J8S4F3
Conclusion
Converting a floating point number to Base36 in C# is not as straightforward as it is in JavaScript, but with the Base36Converter
class provided, you can easily accomplish this task. By following the steps outlined in this article, you can convert any floating point number to Base36 and use it in your C# applications.