When something is called “alphanumeric,” it means that it is made up of both letters and numbers. So, keeping this in mind, alphanumeric characters include all 26 letters of the English alphabet and the numbers 0 through 9. In alphanumeric codes, you can also use standard symbols, mathematical symbols, and punctuation marks like @, #, and!.
What does it mean to be alphanumeric?
Merriam-Webster says that the word “alphanumeric” is an adjective made up of the words “alphabetical” and “numeric.” As was said above, the word “alphanumeric” can include both the Roman numerals 0 through 9 and the letters A through Z, in both uppercase and lowercase. Symbols like @, #, and $ are often used in alphanumeric codes, but it’s important to remember that punctuation and mathematical symbols are not alphanumeric characters.
When working with machines, you have to use alphanumeric language. For example, in the American Standard Code for Information Interchange, which is used by computer programmers, alphanumeric characters are used (ASCII). Also, the English language naturally sorts words in the order of the alphabet. That is, when you put a list of words in alphabetical order, you may notice that a word with a number or a percentage is at the top of the list, even if there are words that start with the letter “a.”
Characters from A to Z
Still not sure what alphanumeric characters are or what alphanumeric codes usually include? Here is a list of all the letters and numbers:
Letters of the alphabet:
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.
Symbols:
@ (“at” sign)
$ (dollar sign)
# (pound sign)
Characters with a twist:
& (ampersand)
* (asterisk)
{ } (braces)
[] (brackets), (comma)
= (equal sign)
– (hyphen)
() (parenthesis) (parenthesis)
. (period)
+ (plus sign)
; (semicolon)
‘ (apostrophe, or single quotation mark)
/ (slash)
On a keyboard, alphanumeric keys are usually spread out over five rows. At the top, there is usually a row of numbers, and the rows below that have letters. Lastly, a functional row of keys, like the space bar or the CTRL, ALT, and FN keys, sits below or sometimes along the sides of the keyboard.
Most likely, you’ve been to a website or logged into an account that required an alphanumeric password. When it comes to cybersecurity, a smart combination of letters and numbers can often make someone safer. Also, you can use alphanumeric characters to name files. However, some symbols, like the slash (/) or question mark (? ), are usually not allowed in file names or other places.
Alphanumeric Examples
The best way to show how letters and numbers work? Taking a look at how they are used in the real world. As was said above, passwords with both letters and numbers are safer. A hacker could figure out your six-character password more easily, for example, if you only used lowercase letters. Most people who use passwords with only lowercase letters also use common words, which makes their passwords even easier to figure out. With this in mind, using passwords with both letters and numbers can make it less likely that your account will be hacked.
Alphanumeric characters are also often used to communicate in central processing units (CPUs). Programmers often talk to each other using only numbers, but each number really stands for a letter. This “language” is called “binary code,” and each letter or number is represented by a different set of “0” and “1” digits. For instance, the letter “A” is written as 01000001.
Want a more common example? Well, alphanumeric characters are also used to figure out where people are sitting on aeroplanes. Row “I” is often skipped on planes so that the letter doesn’t get mixed up with the number 1. Also, car companies do the same thing and don’t use the letters “I,” “O,” and “Q” because they look like the numbers 1 and 0. In the same way, electrical connectors don’t use the letters “I,” “O,” “Q,” “S,” and “Z” to name their pins because they look too much like the numbers 1, 0, 5, 3, and 2. People also used alphanumeric pagers and beepers to get messages in the past.
Alphanumeric Code
Morse code, Baudot code, EBCDIC, UNICODE, and ASCII are all types of alphanumeric code that are often used today. Hollerith code was also used in the past, but it is no longer used because other storage media have become more popular.
Let’s look more closely at the five codes that are still widely used today.
Morse Code was made by Samuel F.B. Morse in the year 1837. It uses a combination of short parts (dots) and long parts (dashes) to show letters, numbers, and special characters. Short and long elements can be represented by sounds, marks, pulses, or keying on and off. For example, the letter A is made up of a dot and a dash. The number 5 is made up of five dots, and the number 10 is also made up of five dots. According to the International Morse code, a dash is the same as three dots.
Baudot Code: The Baudot code is a well-known alphanumeric code. Emile Baudot, a French engineer, came up with it in 1870. This code shows an alphabet with five different parts. Also, all the symbols had the same length of time. This was different from the Morse Code, which let telegraphs send Roman letters, punctuation, and control signals.
ASCII stands for American Standard Code for the Interchange of Information. ASCII codes, which are based on telegraphic codes, are used to represent alphanumeric data in computer input and output. They are based on how the English alphabet is written. ASCII became a standard code in 1967. Since then, it has been updated many times, with the most recent one coming out in 1986.
Seven-bit characters can stand for almost 128 different ones. There are 95 characters that can be printed, including 26 capital letters (A–Z), 26 lowercase letters (a–z), 10 numbers (0–9), and 33 special characters (mathematical symbols, space characters, etc.). Also, it gives the codes for 33 obsolete characters that don’t print anymore, except for carriage return and/or line feed.
EBCDIC stands for Extended Binary Coded Decimal Interchange Code. This code, which you say “ehb-suh-dik” or “ehb-kuh-dik,” was made by IBM and became a common way for computers to send alphanumeric data. As an 8-bit code, it can represent the numbers 0 through 9 by using the 8421 BCD code followed by 1111. So, EBCDIC can hold up to 28 characters, making a total of 256.
Unicode: ASCII and EBCDIC codes have some limitations and can’t be used to process information in more than one language. Unicode comes into play here. Unicode has the most complete character encoding scheme, so it can be used to code and use any text. It stands for 65,536 different characters in 16 bits, which lets it be encoded so computers can use it. It works with many different languages and has a full set of mathematical and technical symbols, which makes it much easier to share scientific information.
