Case sensitivity
In computers, case sensitivity defines whether
Areas of significance
Case sensitivity may differ depending on the situation:
- Searching: Users expect information retrieval systems to be able to have correct case sensitivity depending on the nature of an operation. Users looking for the word "dog" in an online journal probably do not wish to differentiate between "dog" or "Dog", as this is a writing distinction; the word should be matched whether it appears at the beginning of a sentence or not. On the other hand, users looking for information about a brand name, trademark, human name, or city name may be interested in performing a case-sensitive operation to filter out irrelevant results. For example, somebody searching for the name "Jade" would not want to find references to the mineral called "jade". On the English Wikipedia for example a search for friendly fire returns the military article but Friendly Fire (capitalized "Fire") returns the disambiguation page.[NB 1][1]
- Usernames: Authentication systems usually treat usernames as case-insensitive to make them easier to remember, reducing typing complexity, and eliminate the possibility of both mistakes and fraud when two usernames are identical in every aspect except the case of one of their letters. However, these systems are not case-blind. They preserve the case of the characters in the nameso that users may choose an aesthetically pleasing username combination.
- Passwords: Authentication systems usually treat passwords as case-sensitive. This enables the users to increase the complexity of their passwords.
- File names: Traditionally, Unix-like operating systems treat file names case-sensitively while Microsoft Windows is case-insensitive but, for most file systems, case-preserving. For more details, see below.
- Variable names: Some programming languages are case-sensitive for their variable names while others are not. For more details, see below.
- URLs: The path, query, fragment, and authority sections of a URL may or may not be case-sensitive, depending on the receiving web server. The scheme and host parts, however, are strictly lowercase.
In programming languages
Some
In text search
A text search operation could be case-sensitive or case-insensitive, depending on the system, application, or context. The user can in many cases specify whether a search is sensitive to case, e.g. in most text editors, word processors, and Web browsers. A case-insensitive search is more comprehensive, finding "Language" (at the beginning of a sentence), "language", and "LANGUAGE" (in a title in capitals); a case-sensitive search will find the computer language "BASIC" but exclude most of the many unwanted instances of the word. For example, the
Case-insensitive operations are sometimes said to fold case, from the idea of folding the character code table so that upper- and lowercase letters coincide.
In filesystems
In filesystems in
The older
Notes
References
- WP:DIFFCAPS
- ISBN 0-13-110163-3.
- ISBN 0-596-00214-9.
- ^ "Nim Manual: Identifier Equality". nim-lang.github.io. Retrieved 2019-04-27.
- ^ "case-sensitive-search - case sensitive google search - Google Project Hosting". code.google.com. Retrieved 2013-05-20.
- ^ "2.10 Making Queries Case Insensitive". Oracle SQL Developer User's Guide, Release 1.5 (PDF). Oracle Corporation. August 2013.
- ^ "C.5.5.1 Case Sensitivity in String Searches". MySQL 5.0 Reference Manual. MySQL. Retrieved 2013-05-20.
- ^ "Case Sensitivity in Subsystem for UNIX-based Applications". Microsoft Learn. 2005-08-22. Retrieved 2013-05-20.
- ^ "Filenames are Case Sensitive on NTFS Volumes". Microsoft Support. 2006-11-01. Archived from the original on Jul 23, 2013. Retrieved 2013-05-20.