[RESOLVED] Converting a long to a bit string

[thegoldenavatar]

Hi. I've got to access a set of user permissions. There are 32 possible permissions that can be either true or false. The function that gets the permissions returns a long. Each bit in that long (from 0-31) represents one of the options. What I'd like to do is convert that long to a string of 1's and 0's.

For example, if the number came back as 32 I'd like to convert it to
"00000000 00000000 00000000 00010000"

Thanks.

[thegoldenavatar]

In the meantime I found a function to do what I need. For future reference, here it is:

        public string Int32ToBinary(int integerValue)
        {

            string returnVal = string.Empty;
            int remainder = 0;

            for (; integerValue > 0; integerValue /= 2)
            {
                remainder = integerValue % 2;
                returnVal = remainder.ToString() + returnVal;
            }

            returnVal = returnVal.PadLeft(32, '0');

            return returnVal;
        }

Thanks.

[jmcilhinney]

Firstly, to convert a number to a binary string you simply do this:

myString = Convert.ToString(myNumber, 2);

You can pad that with zeroes if you like, taking note that the long type is 64 bits wide, not 32:

myString = Convert.ToString(myNumber, 2).PadLeft(64, '0');

Finally, it would be better to create your own structure for this:

public struct UserPermissions
{
	long value;

	public bool this[int index]
	{
		get
		{
			if (index < 0 || index > 63)
			{
				throw new ArgumentOutOfRangeException("index",
													  index,
													  "Index values must be within the range 0 to 63 inclusive.");
			}

			return Convert.ToBoolean(this.value & Convert.ToInt64(Math.Pow(2, index)));
		}
		set
		{
			if (index < 0 || index > 63)
			{
				throw new ArgumentOutOfRangeException("index",
													  index,
													  "Index values must be within the range 0 to 63 inclusive.");
			}

			if (value)
			{
				this.value |= Convert.ToInt64(Math.Pow(2, index));
			}
			else
			{
				this.value &= (long.MaxValue ^ Convert.ToInt64(Math.Pow(2, index)));
			}
		}
	}

	public UserPermissions(long value)
	{
		this.value = value;
	}

	public long ToInt64()
	{
		return this.value;
	}
}