Javascript Regexp dynamic generation from variables? [duplicate]
You have to use RegExp:
str.match(new RegExp(pattern1+'|'+pattern2, 'gi'));When I'm concatenating strings, all slashes are gone.
If you have a backslash in your pattern to escape a special regex character, (like \(), you have to use two backslashes in the string (because \ is the escape character in a string): new RegExp('\\(') would be the same as /\(/.
So your patterns have to become:
var pattern1 = ':\\(|:=\\(|:-\\(';var pattern2 = ':\\(|:=\\(|:-\\(|:\\(|:=\\(|:-\\(';
Use the below:
var regEx = new RegExp(pattern1+'|'+pattern2, 'gi');str.match(regEx);
You have to forgo the regex literal and use the object constructor, where you can pass the regex as a string.
var regex = new RegExp(pattern1+'|'+pattern2, 'gi');str.match(regex);