# Alphanumeric Characters: What Are They? The Definition of Alphanumeric and Some Common Alphanumeric Code Examples

Something that is alphanumeric is made up of both letters and numbers. With this in mind, alphanumeric characters include all 26 letters of the English alphabet as well as the numerals 0 through 9. Alphanumeric codes also include traditional symbols, mathematical symbols, and punctuation characters such as @, #, and!

## What Is the Definition of Alphanumeric?

Alphanumeric is an adjective that combines the terms “alphabetical” and “numeric,” according to Merriam-Webster. As previously stated, the term “alphanumeric” can refer to both Roman numerals 0 through 9 and uppercase and lowercase letters A through Z. Symbols like @, #, and \$ are frequently used in alphanumeric codes, however it’s vital to remember that punctuation and mathematical symbols are not considered alphanumeric characters.

Working with machines necessitates the use of alphanumeric language. In the American Standard Code for Information Interchange, for example, computer programmers employ alphanumeric characters (ASCII). Furthermore, the English language organises words in an alphabetic order by default. That is, if you arrange a list of words alphabetically, you might find that a term containing a number or a percentage comes first, even though other words begin with the letter “a.”

Alphanumeric Symbols

Still have questions about what constitutes alphanumeric characters, or what is commonly included in alphanumeric codes? The whole list of alphanumeric characters is as follows:

Alphabetic Symbols:

A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z. A, B, C, D, E, F, G, H, I, J, K, L

Symbols:

@ (“at” symbol)

\$ (dollar sign)

# (pound sign)

Characters of Interest:

& (ampersand) (ampersand)

• (asterisk)

{ } (braces)

, (comma)

= (equal sign)

â€“ (hyphen)

() (parenthesis)

. (period)

• (plus sign)

; (semicolon)

‘ (apostrophe, or single quotation mark)

/ (slash)

Alphanumeric keys are commonly spread across five rows on a keyboard, with a numeric row at the top and letters from the alphabet in the rows below. Finally, a functioning row of keys, which contains the space bar and the CTRL, ALT, and FN keys, rests below or to the edges of the keyboard.

You’ve probably come across websites or account sign-ins that demand alphanumeric characters in your password. When it comes to cybersecurity problems, a clever alphanumeric combination can often improve one’s protection. Furthermore, you can generate file names using alphanumeric letters â€” albeit some symbols, such as the slash (/) or the question mark (? ), aren’t allowed in file names or other operations.

Examples in Alphanumeric

What is the most effective technique to depict alphanumeric characters and codes? Examining how they’re employed in regular situations. As previously stated, alphanumeric passwords are more secure. For a six-character password, for example, using only lowercase letters makes it easier for a hacker to figure out your password. Furthermore, most people who prefer lowercase letters only use common words in their passwords, making them much easier to guess. Keeping this in mind, alphanumeric passwords might help to reduce the chances of your account being stolen.

Alphanumeric characters are also commonly employed as a form of communication in central processing units (CPUs). Programmers frequently communicate using only numbers, although each number actually symbolises a letter. Binary code is the “language” in which a different sequence of the digits “0” and “1” represents a specific alphanumeric character. For example, the letter “A” in binary code is 01000001.

Looking for a more realistic example? Airplanes also utilise alphanumeric characters to indicate passenger seating orders. On planes, row “I” is frequently skipped to avoid the letter being confused with the number 1. Additionally, because the letters “I,” “O,” and “Q” are similar to the numbers 1 and 0, automobile manufacturers avoid using them. Electrical connectors avoid using the letters “I,” “O,” “Q,” “S,” and “Z” to name pins since they look too similar to the numbers 1, 0, 5, 3, and 2. People have also utilised alphanumeric pagers and beepers to receive messages in the past.

Code in Alphanumeric

Morse code, Baudot code, EBCDIC, UNICODE, and ASCII are all examples of alphanumeric codes that are extensively used today. People utilised Hollerith code in the past, but it’s now deemed obsolete due to the widespread adoption of other storage medium.

Let’s take a deeper look at the five codes that are still in widespread usage today.

Morse Code: Samuel F.B. Morse invented Morse Code in 1837. To depict letters, numerals, and special characters, it blends short (dots) and longer (dashes) parts. Sounds, markings, pulses, and on-off keying can be used to create symbols for short and long elements. A dot plus a dash, for example, constitute the letter A, five dots form the digit 5, and the same rule (i.e. 10 dots) applies to the digit 10. A dash is equal to three dots in the International Morse Code.

The Baudot code is another widely used alphanumeric code. Emile Baudot, a French engineer, designed it in 1870. This code represents an alphabet using five elements. In contrast to the Morse Code, which allowed telegraphs to carry Roman letters, punctuations, and control signals, all of the symbols were of identical duration.

ASCII stands for American Standard Code for Information Interchange. ASCII codes (pronounced “as-kee”) are used to represent alphanumeric data in computer input/output. They evolved from telegraphic codes. They are based on the English alphabet’s order. ASCII was first published as a standard code in 1967, and it has since undergone numerous modifications, the most recent of which was released in 1986.

Nearly 128 characters can be represented with seven-bit characters. 95 readable characters are included, including 26 uppercase letters (Aâ€“Z), 26 lowercase letters (aâ€“z), ten numeric characters (0â€“9), and 33 special characters (mathematical symbols, space characters, etc.). With the exception of carriage return and/or line feed, it also gives codes for 33 non-printing obsolete characters.

EBCDIC stands for Extended Binary Coded Decimal Interchange Code. IBM invented this code, which is pronounced “ehb-suh-dik” or “ehb-kuh-dik,” and it is commonly used by computers to transport alphanumeric data. It may represent the numbers 0 through 9 as an 8-bit code using the 8421 BCD code prefixed by 1111. EBCDIC, on the other hand, can hold up to 28 characters for a total of 256.

Unicode: ASCII and EBCDIC codes have a few drawbacks and do not allow for multilingual computer processing. Unicode comes into play here. Unicode is the most comprehensive character encoding technique available, allowing computers to encode and use any text.

It can be encoded for use by computers since it represents 65,536 distinct characters in 16 bits. It supports a wide range of languages, as well as a comprehensive set of mathematical and technical symbols, substantially simplifying the interchange of scientific data.

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.