Convert Binary To Decimal Using Array and Loop

Question

I am trying to write a VB function that converts binary to decimal. I need to store the binary length in an array and use a loop to find my answer. I have been trying to figure this out for a while. This is what I have so far maybe you can help.

Public Function binaryToDecimal(ByVal Binary As String)
    Dim myDecimal As Integer
    Dim blength As Integer = Binary.Length
    Dim index(blength) As Integer
    For index = index To 0 Step -1
        myDecimal += Binary * (2 ^ (blength - 1))
        blength = blength - 1
    Next
    Return myDecimal
End Function

Answer 1

I don't understand your code at all... You never even fill the array with anything. Neither do you do anything if the binary string contains zeros ( 0 ).

But if you want to convert binary to decimal, here's a simple approach (and you don't really need an array):

Public Function BinaryToDecimal(ByVal Binary As String) As Integer
    Dim ReturnValue As Integer = 0
    Dim x As Integer = 1
    For i = Binary.Length - 1 To 0 Step -1
        If Binary.Chars(i) = "1"c Then
            ReturnValue += x
        End If
        x += x
    Next
    Return ReturnValue
End Function

The function starts at the end of the string and goes backwards. It increments x by itself for every char, and ReturnValue is incremented by the current x if the current character is '1'.

The function will convert for example 1111 into 15 , 100000 into 32 , and 1011101001 into 745 .

Tested: http://ideone.com/SsZ3d2

Hope this helps!

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EDIT:

It's also worth mentioning that the function does not support spaces in the string. If you want it to do that, just tell me and I'll add that too.