I have what I think are the same expressions one in the sorthand regex format, the other as a RegExp object with a string. I expect they would both be true but that's not what I'm seeing.
/^key$|^key([;,]\skey)+$/.test('key, key; key') //true
var rgxStr = '^key$|^key([;,]\skey)+$'; //
(new RegExp(rgxStr)).test('key, key; key'); //false
What is going on?
Look here:
var rgxStr = '^key$|^key([;,]\skey)+$';
// ^ whoa, a backslash!
In a regular expression literal, JavaScript interprets that backslash as part of the regular expression.
In a normal string literal, JavaScript doesn't know what to do with \s and discards the backslash.
To fix it, escape your backslash in the string literal:
var rgxStr = '^key$|^key([;,]\\skey)+$';
As soon as you're defining regexp in a string - you have to escape backslashes
var rgxStr = '^key$|^key([;,]\\skey)+$';
