This based on this question in StackOverflow. The accepted answer uses Convert.ToString(int, base) to get the binary string, reverses it and converts it back to int. Nice trick!

I have very little experience with bit twidling (using Flags is about it :p ) so I decided to try and code the solution to this problema without using Convert.

I came up with the following solution. I'd like to know easier ways to do this as there are probably many much better than the one I found.

public static IEnumerable<bool> ToBinary(this int n)
{
 for (int i = 0; i < 32; i++)
 {
 yield return (n & (1 << i)) != 0;
 }
}
public static int ToInt(this IEnumerable<bool> b)
{
 var n = 0;
 var counter = 0;
 foreach (var i in b.Trim().Take(32))
 {
 n = n | (i ? 1 : 0) << counter;
 counter++
 }
 return n;
}
private static IEnumerable<bool> Trim(this IEnumerable<bool> list)
{
 bool trim = true;
 foreach (var i in list)
 {
 if (i)
 {
 trim = false;
 }
 if (!trim)
 {
 yield return i;
 }
 }
}

And now you'd use it like this:

var reversed = n.ToBinary().Reverse().ToInt();

This based on this question in StackOverflow. The accepted answer uses Convert.ToString(int, base) to get the binary string, reverses it and converts it back to int. Nice trick!

I have very little experience with bit twidling (using Flags is about it :p ) so I decided to try and code the solution to this problema without using Convert.

I came up with the following solution. I'd like to know easier ways to do this as there are probably many much better than the one I found.

public static IEnumerable<bool> ToBinary(this int n)
{
 for (int i = 0; i < 32; i++)
 {
 yield return (n & (1 << i)) != 0;
 }
}
public static int ToInt(this IEnumerable<bool> b)
{
 var n = 0;
 var counter = 0;
 foreach (var i in b.Trim().Take(32))
 {
 n = n | (i ? 1 : 0) << counter;
 counter++
 }
 return n;
}
private static IEnumerable<bool> Trim(this IEnumerable<bool> list)
{
 bool trim = true;
 foreach (var i in list)
 {
 if (i)
 {
 trim = false;
 }
 if (!trim)
 {
 yield return i;
 }
 }
}

And now you'd use it like this:

var reversed = n.ToBinary().Reverse().ToInt();