How can I convert an int to an array of bool?

How can I convert an int to an array of bool (representing the bits in the inte开发者_StackOverflow中文版ger)? For example:

4 = { true, false, false }
7 = { true, true, true }
255 = { true, true, true, true, true, true, true, true }

An int should map nicely to BitVector32 (or BitArray)

int i = 4;
var bv = new BitVector32(i);
bool x = bv[0], y = bv[1], z = bv[2]; // example access via indexer

However, personally I'd just use shifts (>> etc) and keep it as an int. The bool[] would be much bigger

You can use the BitArray.

var bools = new BitArray(new int[] { yourInt }).Cast<bool>().ToArray();

Int32 number = 10;

var array = Convert.ToString(number, 2).Select(s => s.Equals('1')).ToArray();

--Edit--

Using extension method:

public static class Int32Extensions
{
    public static Boolean[] ToBooleanArray(this Int32 i)
    {
        return Convert.ToString(i, 2 /*for binary*/).Select(s => s.Equals('1')).ToArray();
    }
}

Usage:

var boolArray = number.ToBooleanArray();

You can do this as a two-step process, first convert the integer to a binary (base 2) string representation using Convert.ToString and then iterate over that string to populate a BitArray.

For example:

int someInt = 7;
string binaryString = Convert.ToString(someInt, 2); 
BitArray bitArray = new BitArray(binaryString.Length); 
for (int i = 0; i < bitArray.Length; i++)
{
    bitArray[i] = (binaryString[i] == '1');
}

    public static bool[] Convert(int[] input, int length)
    {
        var ret = new bool[length];
        var siz = sizeof(int) * 8;
        var pow = 0;
        var cur = 0;

        for (var a = 0; a < input.Length && cur < length; ++a)
        {
            var inp = input[a];

            pow = 1;

            for (var i = 0; i < siz && cur < length; ++i)
            {
                ret[cur++] = inp > 0 ? (inp & pow) != 0 : (inp & pow) == 0;

                pow *= 2;
            }
        }

        return ret;
    }

You can use the BitArray to easily get a collection of booleans from a number:

var b = new BitArray(new int[] { 255 });

However, it will use all the bits in the value, so the above will get you a BitArray with the length 32 as the int data type is 32 bits.

You can create a BitArray from bytes, which would give you eight booleans from each byte:

var b = new BitArray(new byte[] { 255 });

You can get an array with only the significant bits by skipping the leading falses:

bool[] b = new BitArray(42).Cast<bool>().SkipWhile(x => !x).ToArray();