In JavaScript:
"ab abc cab ab ab".replace(/\bab\b/g, "AB");
correctly gives me:
"AB abc cab AB AB"
When I use utf-8 characters though:
"αβ αβγ γαβ αβ αβ".replace(/\bαβ\b/g, "AB");
the word boundary operator doesn't seem to work:
"αβ αβγ γαβ αβ αβ"
Is there a solution to this?
The word boundary assertion does only match if a word character is not preceded or followed by another word character (so .\b. is equal to \W\w and \w\W). And \w is defined as [A-Za-z0-9_]. So \w doesn’t match greek characters. And thus you cannot use \b for this case.
What you could do instead is to use this:
"αβ αβγ γαβ αβ αβ".replace(/(^|\s)αβ(?=\s|$)/g, "$1AB")
"αβ αβ", the first match would consume "αβ |αβ" (| indicates the internal pointer) and the last part would not be matched because there is no leading space left. But since the look-ahead assertion does not consume characters, the position of the pointer after the first match will be "αβ| αβ" and the leading space is preserved for the next match.
αβ! for instance.
Not all Javascript regexp implementation has support for Unicode ad so you need to escape it
"αβ αβγ γαβ αβ αβ".replace(/\u03b1\u03b2/g, "AB"); // "AB ABγ γAB AB AB"
For mapping the characters you can take a look at http://htmlhelp.com/reference/html40/entities/symbols.html
Of course, this doesn't help with the word boundary issue (as explained in other answers) but should at least enable you to match the characters properly
\u03b1 supposed to be interpreted?I needed something to be programmable and handle punctuation, brackets, etc.
var wordToReplace = '買い手',
replacementWord = '[[BUYER]]',
text = 'Mange 買い手 information. The selected Store and Classification will be the default on the สั่งซื้อ.'
function replaceWord(text, wordToReplace, replacementWord) {
var re = new RegExp('(^|\\s|\\(|\'|"|,|;)' + wordToReplace + '($|\\s|\\)|\\.|\'|"|!|,|;|\\?)', 'gi');
return text.replace(re, replacementWord);
}
I've written a javascript resource editor so this is why I've found this page and also answered it out of necessity since I couldn't find a word boundary parametarized regexp that worked well for Unicode.
Not all the implementations of RegEx associated with Javascript engines a unicode aware.
For example Microsofts JScript using in IE is limited to ANSI.
When you’re dealing with Unicode and natural-language words, you probably want to be more careful with boundaries than just using \b. See this answer for details and directions.
UTF-8for Unicode. According to the standard an implementation may use eitherUCS-2orUTF-16I believe. This means either you are operating on text that has been converted to one of these formats, or you could be operating on text where each "octet" (byte) of each Unicode codepoint has been converted to one of these formats, depending on how your code gets the text.