Java – Convert int to Byte Array of 4 Bytes? [duplicate]
You can convert yourInt to bytes by using a ByteBuffer like this: return ByteBuffer.allocate(4).putInt(yourInt).array(); Beware that you might have to think about the byte order when doing so.
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How to convert between bytes and strings in Python 3?
The ‘mangler’ in the above code sample was doing the equivalent of this: bytesThing = stringThing.encode(encoding=’UTF-8′) There are other ways to write this (notably using bytes(stringThing, encoding=’UTF-8′), but the above syntax makes it obvious what is going on, and also what to do to recover the string: newStringThing = bytesThing.decode(encoding=’UTF-8′) When we do this, the … Read more
Why is the range of bytes -128 to 127 in Java?
The answer is two’s complement. In short, Java (and most modern languages) do not represent signed integers using signed-magnitude representation. In other words, an 8-bit integer is not a sign bit followed by a 7-bit unsigned integer. Instead, negative integers are represented in a system called two’s complement, which allows easier arithmetic processing in hardware, … Read more
Set specific bit in byte
Use the bitwise OR (|) and AND (&) operators. To set a bit, namely turn the bit at pos to 1: my_byte = my_byte | (1 << pos); // longer version, or my_byte |= 1 << pos; // shorthand To un-set a bit, or turn it to 0: my_byte = my_byte & ~(1 << pos); … Read more
When to use byte array & when byte buffer?
There are actually a number of ways to work with bytes. And I agree that it’s not always easy to pick the best one: the byte[] the java.nio.ByteBuffer the java.io.ByteArrayOutputStream (in combination with other streams) the java.util.BitSet The byte[] is just a primitive array, just containing the raw data. So, it does not have convenient … Read more
Byte Array in Python
In Python 3, we use the bytes object, also known as str in Python 2. # Python 3 key = bytes([0x13, 0x00, 0x00, 0x00, 0x08, 0x00]) # Python 2 key = ”.join(chr(x) for x in [0x13, 0x00, 0x00, 0x00, 0x08, 0x00]) I find it more convenient to use the base64 module… # Python 3 key … Read more
How to convert byte[] to Byte[] and the other way around?
byte[] to Byte[] : byte[] bytes = …; Byte[] byteObject = ArrayUtils.toObject(bytes); Byte[] to byte[] : Byte[] byteObject = new Byte[0]; byte[] bytes = ArrayUtils.toPrimitive(byteObject);
What is the maximum number of bytes for a UTF-8 encoded character?
The maximum number of bytes per character is 4 according to RFC3629 which limited the character table to U+10FFFF: In UTF-8, characters from the U+0000..U+10FFFF range (the UTF-16 accessible range) are encoded using sequences of 1 to 4 octets. (The original specification allowed for up to six byte character codes for code points past U+10FFFF.) … Read more
System where 1 byte != 8 bit? [duplicate]
On older machines, codes smaller than 8 bits were fairly common, but most of those have been dead and gone for years now. C and C++ have mandated a minimum of 8 bits for char, at least as far back as the C89 standard. [Edit: For example, C90, ยง5.2.4.2.1 requires CHAR_BIT >= 8 and UCHAR_MAX … Read more
Write bytes to file
If I understand you correctly, this should do the trick. You’ll need add using System.IO at the top of your file if you don’t already have it. public bool ByteArrayToFile(string fileName, byte[] byteArray) { try { using (var fs = new FileStream(fileName, FileMode.Create, FileAccess.Write)) { fs.Write(byteArray, 0, byteArray.Length); return true; } } catch (Exception ex) … Read more