In my code, I am using the following regular expression:
var re = new RegExp("(^|\\s)" + classname + "(\\s|$)");
I know that \s represents a white-space character and the caret symbol denotes the "beginning with". However, I am confused about the pipe character in this expression...
Can someone please explain how the above expression can be interpreted in English?
Thank you,
When you see the expression (^|\s), it represents an alternation. This signifies "either the beginning of the text or a space character". Likewise, (\s|$) signifies "either the end of the text or a space character".
Such a type of regex is handy for locating a word in a list separated by spaces without any spaces at the beginning or end.
In the world of JavaScript regex, the | symbol is used to denote "or".
For a comprehensive list of special characters, be sure to visit: https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/RegExp#Special_characters_in_regular_expressions I discovered this resource on the fantastic regex testing platform known as regexpal.com
The | symbol denotes the concept of "or" -
It signifies the beginning of a line (^) or a space character
It corresponds to the value of the
classnamevariableIt indicates a space character or the end of a line ($)
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