How to convert from decimal to binary .NET

Question

I'm a bit confused on decimal to binary number conversion. Here's my code:

Public Class Form1

    Private Sub tbxDecimal_TextChanged(sender As Object, e As EventArgs) Handles tbxDecimal.TextChanged

        If rdbDecmial.Checked = True And IsNumeric(tbxDecimal.Text) Then
            Dim bin, dec As Double
            Dim output As String
            dec = Convert.ToDouble(tbxDecimal.Text)
            For i = 1 To dec Step (???)
                dec = i Mod 2
                If i Mod 2 = 0 Then
                    bin = 0
                Else
                    bin = 1
                End If
                output &= Convert.ToString(bin)
            Next
            tbxBinary.Text = output
        End If
    End Sub
End Class

If I typed in a decimal number in one box, the incorrect numbers come out. I know I have to have some kind of stepping size for this loop, however what should I put in?

I know this question posted long time ago, but.... will any of provided answers convert **decimal** to binary? I don't think so. Or question is titled wrong, or all provided answers are incorrect. — nelek, Aug 30 '15 at 20:52

score 1 · Answer 1 · answered Feb 03 '14 at 19:36

You need a While, not a For; you should loop as long as dec is not 0. Also, you should treat the number as Integer rather than Double; this algorithm only works for integers. Another issue is that you're concatenating the bits in the wrong order.

Private Function ToBinary(dec As Integer) As String
    Dim bin As Integer
    Dim output As String
    While dec <> 0
        If dec Mod 2 = 0 Then
            bin = 0
        Else
            bin = 1
        End If
        dec = dec \ 2
        output = Convert.ToString(bin) & output
    End While
    If output Is Nothing Then
        Return "0"
    Else
        Return output
    End If
End Function

BTW, I assume you're doing that manually for learning purposes, but if you're not, you can just use the Convert.ToString method:

output = Convert.ToString(dec, 2)

Actually it gives me `"1"` as output where I should expect `"000001"` — Revolucion for Monica, Jul 11 '16 at 09:42
@Marine1 why do you expect that? you need to pad it with the number of 0 you want. How could it now if you want it on 8, 16, 32 or 64 bits? — Thomas Levesque, Jul 11 '16 at 12:00

Andrew Morton · Answer 2 · 2014-02-03T20:10:38.510

1

There is a built-in conversion to a binary string representation which you could use, and you can also use TryParse to make sure the text can be converted to a number (IsNumeric can be a bit more permissive than you might want):

Private Sub tbxDecimal_TextChanged(sender As Object, e As EventArgs) Handles tbxDecimal.TextChanged
    If rdbDecmial.Checked Then
        Dim num As Int64
        If Int64.TryParse(tbxDecimal.Text, num) Then
            tbxBinary.Text = Convert.ToString(num, 2)
        Else
            tbxBinary.Text = ""
        End If
    End If

End Sub

edited Feb 03 '14 at 20:10

answered Feb 03 '14 at 19:59

Andrew Morton

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Are you sure that your way calculate the correct binary? I tried it with 1399775318 and don't get the expected 1010100100100010010000010101010 – PeterCo Jan 18 '17 at 10:29
@PeterCo You should expect 1010011011011101110000001010110. – Andrew Morton Jan 18 '17 at 10:36
So you say the other two examples calculates both wrong? – PeterCo Jan 18 '17 at 10:42
@PeterCo It is *unlikely* that a Framework method would be wrong. Are you using Option Strict On so that all your variable types match up? – Andrew Morton Jan 18 '17 at 10:44
@PeterCo When Kaz-LA's method is modified to work with Option Strict On, it too gives 1010011011011101110000001010110. – Andrew Morton Jan 18 '17 at 10:48
You are right. With "Option Strict on" I see the probem too. Thank you for that hint! – PeterCo Jan 18 '17 at 11:02

score 0 · Answer 3 · edited May 23 '17 at 11:45

0

Heres the VB.NET version for you

Dim decimalNumber As Integer = Integer.Parse(tbxDecimal.Text)

Dim remainder As Integer
Dim result As String = String.Empty
While decimalNumber > 0
    remainder = decimalNumber Mod 2
    decimalNumber /= 2
    result = remainder.ToString() & result
End While
Console.WriteLine("Binary:  {0}", result)

Source: Decimal to binary conversion in c #

edited May 23 '17 at 11:45

Community

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answered Feb 03 '14 at 19:37

spajce

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score 0 · Answer 4 · edited Jan 18 '17 at 10:50

0

C#:

static string DecimalToBinary(int num) 
{
    var bin = new System.Text.StringBuilder();
    do
    {
      bin.Insert(0, (num%2));
      num/=2;
    }while (num != 0);

    return bin.ToString();
}

VB:

Private Shared Function DecimalToBinary(num As Integer) As String
   Dim bin = New System.Text.StringBuilder()
      Do
         bin.Insert(0, (num Mod 2))
         num /= 2
      Loop While num <> 0

   Return bin.ToString()
End Function

edited Jan 18 '17 at 10:50

PeterCo

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answered Feb 03 '14 at 19:49

Kaz-LA

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Your VB version does not work correctly due to the line `num /= 2` because the invisible R.H.S. is a double and the implicit conversion to an integer uses rounding, not truncation. E.g. with 1399775318 your method gives 1010100100100010010000010101010 but the correct answer is 1010011011011101110000001010110. To correct it, use `num = num \ 2` (or `num \= 2`). – Andrew Morton Jan 18 '17 at 11:14

score 0 · Answer 5 · edited Jan 18 '17 at 11:57

Take this code to your btnCalc and paste it

Dim iptbxNumberDec as integer

Dim iptbxNumber as string

Dim intBin as integer

iptbxNumber = inputbox("Please enter the number that you want to convect to binary from decimal","Number ")

integer.tryparse(iptbxNumber,iptbxNumberDec)

if iptbxNumberDec > 0 then 

iptbxNumberDec / = 10

Do while iptbxNumberDec <> 0

if iptbxNumberDec mod 2 = 0 then

intBin = 0 

lblOutput.text = vbcrlf & vbcrlf & intBin & " " 

else

intBin = 1 

lblOutput.text = vbcrlf & vbcrlf & intBin & " " 

iptbxNumber / = 10

Do while iptbxNumberDec <> 0

if iptbxNumberDec mod 2 = 0 then

intBin = 0

lblOutput.text = vbcrlf & vbcrlf & intBin & " " 

else

intBin =  1

lblOutput.text = vbcrlf & vbcrlf & _
intBin & " "

intBin += 1 

endif



loop

endif

use this code in visual basic

score 0 · Answer 6 · answered May 06 '15 at 13:44

So my solution with ULong and Option Strict On.

For example: num = 4036854942 and the result is: 11110000100111011000010010011110

Compare it with: http://unicode-table.com/en/1D11E/

Private Shared Function DecimalToBinary(num As ULong) As String

    Dim bin = New System.Text.StringBuilder()

    Dim modnum As Decimal

    Do
        modnum = num Mod 2
        bin.Insert(0, (modnum))
        num = CType((num - modnum) / 2, ULong)

    Loop While num <> 0

    Return bin.ToString()

End Function

score 0 · Answer 7 · answered Jan 10 '19 at 19:07

Dim str_bianry as String
Dim index_number as integer =65

while index_number > 0
str &= index_number MOD 2
index_number \=2
end loop

Dim char_binary as char=str.toArray()
Array.Reverse(char_binary)
msgbox(String.join("",char_binary).padLeft(8,"0"))

score 0 · Answer 8 · answered Dec 11 '19 at 11:00

VB:

Function DecimalToBinary(num As Integer) As String

    Dim Binary_String As String

    Binary_String = ""

    Do While num > 0
        Binary_String = num Mod 2 & Binary_String
        num = num \ 2
    Loop

    Return Binary_String

End Function

Daniel Vilela · Answer 9 · 2022-05-20T02:47:25.860

0

My solution in VB.Net:

Sub Main(args As String())

    Dim number As Integer = 14
    Dim binary As String

    While number > 0
        Dim temp As String = number Mod 2
        number = Floor(number / 2)  

        binary += temp
    End While

    Console.WriteLine(binary.Reverse.ToArray)

End Sub

edited May 20 '22 at 02:47

answered May 20 '22 at 02:46

Daniel Vilela

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How to convert from decimal to binary .NET

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