Question

I have

Dim bv As New Specialized.BitVector32(25)
Dim sb As String = "0b" 'I resisted the urge to use a stringbuilder

For i As Integer = 31 To 0 Step -1
    sb &= IIf(bv(i), 1, 0)
Next

Console.WriteLine(sb)

And I get

0b00000011000000110000001100000011

I only wanted to use BitVector32 for bit flags and I wanted the output to be

0b00000000000000000000000000011001

How do I set this up properly?

Answer 1

The argument to BitVector32 is a mask, not a bit offset. BitArray is probably closer to what you want.

(edit) hmmm – maybe the easiest thing is to use shift operators; in C#:

    for(int i = 31 ; i >= 0; i--) {
        sb += bv[1 << i] ? "1" : "0";
    }

Also note that index 0 refers to the LSB – so you need to reverse the loop.

Or easier:

Convert.ToString(25, 2).PadLeft(32, '0');