![bits in a byte bits in a byte](https://image.slidesharecdn.com/csc103bitsbytesbinary-190217154903/95/ccs103-bits-bytes-binary-20-638.jpg)
![bits in a byte bits in a byte](https://www.homenethowto.com/wp-content/uploads/table-bits-bytes-k-m-g-t.png)
Yep, that’s right: a C++ byte might have more than 8 bits. But, but, but what about machines where a char has more than 8 bits? Surely you’re not saying a C++ byte might have more than 8 bits, are you?!?
![bits in a byte bits in a byte](http://www.bodurov.com/BytesViewer/BytesViewer.gif)
Take a deep breathĪnd repeat after me: “character and char might be different.” There, doesn’t that feel better? No? Well keep reading I’m really sorry if that hurts, but believe me, it’s better to get all the pain over with at once. Yes that’s right: the thing commonly referred to as a “character” might be different from the thing C++ calls a
![bits in a byte bits in a byte](https://yeni-kimlik.com/images/b_2021/1-byte-kac-bit.jpg)
Are you saying that a “character” and a char might be different?!? Whoa, but what about machines or compilers that support multibyte characters. One, one, one,Įxactly one byte, always one byte. What are the units of sizeof?įor example, if sizeof(Fred) is 8, the distance between two Fred objects in an array of Freds will be exactly 8Īs another example, this means sizeof(char) is one byte. The pain will go away by sometime next week. Look, I know this is going to hurt your head, so please, please just read the next few FAQs in sequence and hopefully Never, never, never.Įven if you think of a “character” as a multi-byte thingy, char is not. Neither of these claims is well substantiated and are probably false.Īlso playful, but less well known, is the term nybble or nibble, meaning half a byte, or four bits.Built-in / Intrinsic / Primitive Data Types Can sizeof(char) be 2 on some machines? For example, what about double-byte characters? Another suggestion is that it is from BinarY TErm. Some have suggested that it is an abbreviation for BInary digiT Eight and that the Y was substituted for the I so to prevent typographical confusion with bit. Fixed-length fields of length one, two, four, and eight are termed bytes, halfwords, words, and double words respectively. A consecutive group of n such units constitutes a field of length n. Blaauw and Brooks in a 1964 issue of the IBM Systems Journal:Īn 8-bit unit of information is fundamental to most of the formats. The first citation in the Oxford English Dictionary is from an article by Messrs. Over time, the predominant sense shifted to mean eight bits exactly. The original sense of the term was the amount of data required to represent one character-usually, but not always, eight bits. The term byte is of less certain origin, but probably was coined by someone at IBM (perhaps a Dr. Tukey.Īs Shannon indicates, bit is an abbreviated form of binary digit, chosen probably because it is also a play on the meaning of the then existing word bit signifying a small part. If the base 2 is used the resulting units may be called binary digits, or more briefly bits, a word suggested by J. The choice of a logarithmic base corresponds to the choice of a unit for measuring information. The fact that it is the first known use of bit is simply a footnote to its scientific importance.) In the paper, Shannon credits a J.W. (This paper is one of the seminal works of modern information theory. Shannon in Bell Systems Technical Journal in July and October of that year. It first appears in A Mathematical Theory of Communication by C.E. Of the two, bit is older, dating to 1948. Many people wonder where these two computer terms come from.