Escape character
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In computing and telecommunication, an escape character is one which has a special meaning in a sequence of characters.
Usually, it signifies that what is to follow is from a different character code, i.e., have meanings other than normal.
- In alphabet coding schemes, a specially designated character, the occurrence of which in the data signifies that one or more of the characters to follow are from a different character code, i.e., have meanings other than normal.
- In a text-control sequence of characters, a control character that indicates the beginning of the sequence and the end of any preceding text. This is for instance used to control character terminals and printers (see escape sequence).
- In the ASCII character code, the character ESC with decimal code 27 and hexadecimal code 1B.
For example, escape characters are used in combination with special characters in computer programming or in computer scripting when you want to use these special characters within a text which would normally cause the text to behave in a way you wouldn't want it to behave.
Wikipedia, for example boldens text when you type the syntax string ''' (three apostrophes) left and right from the string you want to bolden. As the string ''' already is used for syntax purposes, every time you want to type these three apostrophes within a text will result in Wikipedia to think you want to bolden the text rather than displaying '''. To be able to write the three apostrophes without Wikipedia to interpret it as a bolding command, you have to use the <nowiki></nowiki> escape string.
Escape characters and escape strings can be quite awkward to use (as it was to write this article), as it blows up the syntax, and makes it quite difficult to read, especially when you want to use escape characters to escape characters, as it was used to escape the nowiki-command: <nowiki><nowiki></nowiki></nowiki>
Looking at the syntax of this article can greatly help you understand the concept of escaping.
Some of this article is based on material from Federal Standard 1037C