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Alphanumeric is a combination of alphabetical and numerical characters and is used to describe the collection of Latin letters and Arabic digits or a text constructed from this collection. Merriam-Webster suggests that the term “alphanumeric” may often additionally refer to other symbols, such as punctuation and mathematical symbols. Alphanumeric, also known as alphameric, simply refers to the type of Latin and Arabic characters representing the numbers 0 – 9, the letters A – Z (both uppercase and lowercase), and some common symbols such as @ # * and &.
Sites requesting that you create an alphanumeric password are asking us to use a combination of numbers and letters, which creates stronger passwords. We also use alphanumeric keys to create file names, although there are some symbols that are not accepted as part of a file name, such as a slash (/). That doesn’t seem very secret, does it? The ‘secret’ language part comes into play when we start talking about alphanumeric characters in terms of actual computer programming.
Alphanumeric Characters
Since computers (or central processing units, to be specific) use machine language in the form of numbers to communicate, computer programmers need to write their instructions using numbers rather than alphabet characters. To do this, programmers use numeric representations of what humans see as alphabet characters. You’ve probably seen or heard of binary code that uses only 0s and 1s to represent an alphanumeric character. Computer programmers can use a series of 0s and 1s to represent any character they wish. For example, in binary, the letter ‘A’ would be written as 01000001.
Another way computer programmers represent alphanumeric characters is to use ASCII. ASCII stands for American Standard Code for Information Interchange.
Now, you are probably thinking to yourself, ‘I can key those numbers from my keyboard or number pad, and all I get are numbers!’ You would be correct. In order to use those numbers as ASCII code, you need to be using a text-only program such as Notepad (or save a Word document as text only by choosing the plain text option). Using the ASCII table, a computer programmer can represent the word ‘red’ using the numbers 82 69 68. This is true unless they wanted it in lower case letters, in that case, it would be 114 101 100.
What Are Alphanumeric Characters?
Alphanumeric characters comprise the combination of the twenty-six characters of the alphabet (from A to Z) and the numbers 0 to 9. Therefore, 1, 2, q, f, m, p, and 10 are all examples of alphanumeric characters. Symbols like *, & and @ are also considered alphanumeric characters.
These characters can also be used in combination. Examples of alphanumeric characters made of the combination of special symbols, numbers, and the characters of the alphabet are &AF54hh, jjHF47, @qw99O. The characters of the alphabet can either be in lower case or upper case. The context of use determines whether or not case sensitivity is applied.
When coding, some alphanumeric sets exclude letters that can be easily confused with numbers. For instance, airlines and auto manufacturers both skip the lowercase letter I to avoid confusion with the numeral 1. Auto manufacturers also skip O and Q to avoid confusion with the numeral 0. Other applications do not use the letter S because of its similarity to the numeral 5, or the letter Z because of its similarity to the numeral 2.
The way non-alphanumeric characters that are not defined as search characters are treated depends on whether they are considered punctuation characters or symbols.
Non-alphanumeric Characters
Non-alphanumeric characters considered to be punctuation are treated as white space. In a multi-word search with the words separated by punctuation characters, word order is preserved as if it were a phrase search. The following characters are considered to be punctuation:! @ # & ( ) – [ { } ] : ; ‘, ? / *
Non-alphanumeric characters that are considered to be symbols are also treated as white space. However, unlike punctuation characters, they do not preserve word order in a multi-word search. If a symbol character is adjacent to a punctuation character, the symbol character is ignored. That is to say, the combination of the symbol character and the punctuation character is treated the same as the punctuation character alone. For example, a search on ice-cream would return the same results as a phrase search for “ice cream”, while a search for ice~cream would return the same results as simply searching for ice cream. A search on ice-~cream would behave the same way as a search on ice-cream. Symbol characters include the following: ` ~ $ ^ + = < > “
Alphanumeric Characters List
Alphanumeric characters
- alphabetic characters A through Z
- numeric characters 0 through 9
National characters
- at sign @
- dollar sign $
- pound sign #
Special characters
- ampersand &
- asterisk *
- blank
- braces { }
- brackets [ ]
- comma ,
- equal sign =
- hyphen –
- parenthesis ( )
- period .
- plus sign +
- semicolon ;
- single quotation mark ‘
- slash /
Alphanumeric Characters Meaning
The definition of alphanumeric is something that contains letters and numbers. A password that requires both letters and numbers is an example of an alphanumeric password. A computer keyboard is an example of an alphanumeric keyboard. Alphanumeric, also known as alphameric, simply refers to the type of Latin and Arabic characters representing the numbers 0 – 9, the letters A – Z (both uppercase and lowercase), and some common symbols such as @ # * and &. Sites requesting that you create an alphanumeric password are asking us to use a combination of numbers and letters, which creates stronger passwords. We also use alphanumeric keys to create file names, although there are some symbols that are not accepted as part of a file name, such as a slash (/).
Also, we can understand by this method:
- When a string of mixed alphabets and numerals is presented for human interpretation, ambiguities arise. the foremost obvious is that the similarity of the letters I, O and Q to the numbers 1 and 0. Therefore, counting on the appliance, various subsets of the alphanumeric were adopted to avoid misinterpretation by humans.
- In passenger aircraft, aircraft seat maps and seats were designated by row number followed by column letter. For widebodied jets, the seats are often 10 across, labeled ABC-DEFG-HJK. The letter I skipped to avoid mistaking it as row no 1.
- In the Vehicle number employed by automobile manufacturers, the letters I, O, and Q are omitted for his or her similarity to 1 or 0.
- Tiny embossed letters are wont to label pins on a V.35/M34 electrical connector. The letters I, O, Q, S, and Z were dropped to ease eye strain with 1, 0, 5, 3, and 2. That subset is known as the DEC Alphabet after the corporate that first used it.
- For alphanumerics that are frequently handwritten, additionally to I and O, V is avoided because it’s like U in cursive and Z for its similarity to 2.