ASCII code and Unicode are widely familiar terms for programmers and software developers. By assigning a number to each character, in these two encoding standards a block of text is encoded entirely by numeric numbers. Though these two data representations may seem similar, there exists a huge difference between them. Stick with us to see the relation and comparison of ASCII vs Unicode.
ASCII (American Standard Code for Information Interchange) is a commonly used encoding format that is based on ordering the English alphabet. Each character (letters, numbers, and symbols) is represented with a 7-bit unique binary number here. It is a code for representing a total of 2^7 (=128) characters maximum.
For example, an uppercase A is assigned with a decimal number 65. Decimal 33 refers to the exclamation mark. The first 33 characters are non-printing characters like ESC, carriage return, line feed tab, etc. and the rest of that are printing characters. The equivalent binary of the decimal number is used for each character to store them as a computer only recognizes binary numbers.
ASCII was first commercially applied by Bell data services and was designed for teletypes. The work on ASCII started on October 6, 1960, by ANSI. It was formed to facilitate communication between computers using the common English Language.
Most computers reserve one byte or eight bits for an ASCII character. The last bit is reserved as a parity bit to avoid possible errors of communication. After some time by using the last bit, ASCII Extended was introduced with a maximum of 256 characters. There are other coding systems like EBCDIC and ANSI.
You can map back and forth between a character and a number using the ASCII lookup table given below.
Asci characters are used in our computer keyboards and on the internet particularly in data conversion, email transmission, text files, and programming in C language. Also, UNIX and DOS-based operating systems use ASCII format.
Programmers use ASCII to do calculations on characters. For example, decimal 32 is added and subtracted to convert to a lower case and uppercase latter letter respectively. They are also used in graphic arts.
Unicode is a versatile encoding format for different languages by which each character is assigned with a unique numeric value that is applicable no matter what is the platform. It was formed to facilitate communication between computers and devices used worldwide without any translation.
With the internationalization of the computer world, in 1991 Unicode standard was introduced. It was developed and promoted by a nonprofit organization Unicode Consortium.
There are three different types of Unicode implementations like UTF-8, UTF-16, and UTF-32. Unicode uses different bit patterns like 8, 16, or 32 bits for different characters. It is large enough to support up to 1,114,112 characters.
Unicode set is divided into 17 areas called coding plains. Each of these has 65,536 code points. Each of these areas is further divided into blocks with a different unique purpose.
Unicode can encode most of the languages like Arabic, Chinese, Greek, French, Armenian and so one. Here, each unique numeric code is called a code point. For example, Unicode for some emojis are:
Similarities of ASCII and Unicode
ASCII and Unicode format is based on the same simple idea of representing texts using numbers. This is done to easily store them in computer memory as computers only recognize numbers.
ASCI is a subset of Unicode. The first 128 characters of plain zero of Unicode comprise the ASCII subset of Unicode. So, all of the ASCI codes exist within Unicode.
Both are standard encoding formats and both have significant roles in the development of web-based communication. Both use an integer to represent each character for comparison.
Difference between ASCII and Unicode
ASCII is an American encoding format where Unicode is a universal encoding format. ASCI had two limitations. First, for the keyboards that have special keys, only 128 characters of ASCII is not enough. Second, ASCII only uses the English language as America was the center of the computer industries.
So, the design goal of Unicode was to form a unique code point for every possible character and also to have backward compatibility with ASCII.
The main difference between these two lies in the encoding process and amounts of bits used. The size of a Unicode character varies depending on three encoding schemes but there is no such case in ASCII. ASCII uses only one byte two represent a single character.
As ASCII can represent only 128 characters and Unicode can allocate around 1 million characters, Unicode is more standardized and versatile than ASCII as it is capable to represent emojis, mathematical symbols, and most written languages in the world. For example, ASCII cannot read pound or umlaut.
Also, ASCII codes occupy less memory than Unicode for the small bit pattern. This is the main advantage of ASCII over Unicode. Unicode is little complex and many software and email cannot interpret Unicode character sets.
ASCII vs Unicode both are standard coding representations to make the computer identify every single character of a text. To avoid coding mistakes, it is essential to understand the comparison of ASCII vs Unicode. In this article, we briefly discussed ASCII and Unicode, their similarities and difference.
To sum up, Unicode was brought into existence to overcome the limitations of ASCII and to enhance multilingual communication worldwide. But still, ASCII is used in our computer keyboards as they have many advantages over Unicode.