In computing, a what is a non alphanumeric character is any character that is not a number or letter in the standard Latin alphabet. Most common punctuation marks, such as the period, comma, and apostrophe, are considered non alphanumeric characters.
Other examples of non alphanumeric characters:
- The at sign (@)
- The dollar sign ($)
- The percent sign (%)
- The caret (^)
- The ampersand (&)
- Theasterisk (*)
- The plus sign (+)
- The equal sign (=)
- The left parenthesis (()
- The right parenthesis ())
- The minus sign (-)
While non alphanumeric characters may seem like nothing more than symbols on a keyboard, they actually play an important role in computing. One of the most common uses for non alphanumeric characters is in passwords. Many websites and computer programs will not allow passwords to be entirely alphanumeric in order to make them more difficult to guess. For instance, a password such as “password” would not be considered secure enough because it consists entirely of letters and is only eight characters long. A more secure password might be “p@ssw0rd” because it includes both letters and numbers and is also longer than eight characters.
Another common use for non alphanumeric characters is in email addresses. Email addresses typically include an “@” symbol followed by the domain name of the email provider. For example, the email address “[email protected]” includes the “@” symbol followed by “gmail.com,” which is the domain name of Google’s email service. Without the “@” symbol, an email address would not be valid.
Delimiters can be any character, but they are often non-alphanumeric because alphanumeric characters are often used within strings themselves. Additionally, using a non-alphanumeric character as a delimiter minimizes the likelihood of accidentally including the delimiter character within the string itself.
Another common use for non-alphanumeric characters is in Boolean expressions. A Boolean expression evaluates to either true or false, and it can include any kind of operator, including a non-alphanumeric one. For example, the expression (a < b) is evaluating whether the value of a is less than the value of b. In this case, the less than symbol (<) is serving as an operator.
Operators can be any character, but they are often non-alphanumeric because alphanumeric characters are often used as operands within Boolean expressions themselves. Additionally, using a non-alphanumeric character as an operator minimizes the likelihood of accidentally including the operator character within the operands themselves.
Finally, non alphanumeric characters are often used in URL strings in order to separate different pieces of information. For example, the URL “https://www.example.com/blog/this-is-an-example-post” includes several non alphanumeric characters including “/,” “-,” and “.” These characters help to delineate between the different parts of the URL so that a web browser knows how to process it correctly.
Non alphanumeric characters may seem like nothing more than symbols on a keyboard, but they actually play an important role in computing by helping to make passwords more secure, separating different pieces of information in URLs, and forming email addresses. Next time you see a non alphanumeric character on your keyboard, you’ll know that it serves a purpose beyond just taking up space!