CODEWITHSUNDEEP
c#bitconverter
SanVEE
SanVEE

Reputation: 2070

Converting byte array to hexadecimal value using BitConverter class in c#?

I'm trying to convert a byte array into hexadecimal value using Bitconverter class.

long hexValue = 0X780B13436587;
byte[] byteArray = BitConverter.GetBytes ( hexValue );
string hexResult = BitConverter.ToString ( byteArray );

now if I execute the above code line by line, this is what I see

enter image description here

I thought hexResult string would be same as hexValue (i.e. 780B13436587h) but what I get is different, am I missing something, correct me if I'm wrong.

Thanks!

Upvotes: 1

Views: 2048

Answers (3)

Marc Gravell
Marc Gravell

Reputation: 1064044

Endianness.

BitConverter uses CPU-endianness, which for most people means: little-endian. When humans write numbers, we tend to write big-endian (broadly speaking: you write the thousands, then hundreds, then tens, then the digits). For a CPU, big-endian means that the most-significant byte is first and the least-significant byte is last. However, unless you're using an Itanium, your CPU is probably little-endian, which means that the most-significant byte is last, and the least-significant byte is first. The CPU is implemented such that this doesn't matter unless you are peeking inside raw memory - it will ensure that numeric and binary arithmetic still works the way you expect. However, BitConverter works by peeking inside raw memory - hence you see the reversed data.

If you want the value in big-endian format, then you'll need to:

  • do it manually in big-endian order
  • check the BitConverter.IsLittleEndian value, and if true:
    • either reverse the input bytes
    • or reverse the output

Upvotes: 5

Vladimir Sadov
Vladimir Sadov

Reputation: 41

It is the same number but reversed.

BitConverter.ToString can return string representation in reversed order: http://msdn.microsoft.com/en-us/library/3a733s97(v=vs.110).aspx

"All the elements of value are converted. The order of hexadecimal strings returned by the ToString method depends on whether the computer architecture is little-endian or big-endian."

Upvotes: 1

Dennis_E
Dennis_E

Reputation: 8904

If you look closely, the bytes in the output from BitConverter are reversed.

To get the hex-string for a number, you use the Convert class:

Convert.ToString(hexValue, 16);

Upvotes: 1

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