I don't know why my regex is incorrect:
var domain = "google\.com\.br";
var reEmail = new RegExp("^([A-Za-z0-9_\-\.])+\@" + domain + "$");
I need this to validate an email. Example below: reEmail.test("[email protected]");
I get this error:
Range out of order in character class
Because you create the RegExp using a String the _\-\. becomes _-. and that is the invalid range.
(It is a range from _ to . and that is not correct)
You need to double escape it:
new RegExp("^([A-Za-z0-9_\\-\\.])+@" + domain + "$");
That way the \\ becomes a \ in the String and then is used to escape the -in the RegExp.
EDIT:
If you create RegExp by String it is always helpful to log the result so that you see if you did everything right:
e.g. your part of the RegExp
console.log("^([A-Za-z0-9_\-\.])+\@");
results in:
^([A-Za-z0-9_-.])+@
- as a valid character in your character group, always place it as either the first or last character in the group (e.g., [-a-zA-Z0-9 _] or [a-zA-Z0-9 _-]). Regex is smart enough to know that you are not specifying a range with that character, if it is in those positions (without needing to escape it with a slash).
#) to the range they might just put it at the beginning (i.e. [#-a-zA-Z0-9_]) and it will take the whole company three days to figure out why it's now broken!this is because RegEx works with STRINGS not numbers, so for 2 digit number ranges like: 1 to 16, you CAN NOT use /[1-16]/ = ERROR NOT A VALID RANGE
You need to do this:
/([1-9]|1[0-6])/;
NOTE: in the above you also need to include VALUE < 17, otherwise regex will match anything that has 6 in it, like 26, 36 etc., as well as other number that you don't want.
You can also go this route:
/1|2|3...|15|16/
in the above you need to replace ... with |4|5.. etc.
See here for REGEX for Ranges: https://3widgets.com/
alternatively, try to use FOR LOOP to filter or test stuff out.
/^([A-Za-z0-9_\-.])+@/!!!