jquery - Using Regex with JqueryUI Validate -

i trying add regex validation jqueryui validator following guidance of jquery validate: how add rule regular expression validation?

$.validator.addmethod(         "regex",         function(value, element, regexp) {             var re = new regexp(regexp);             return this.optional(element) || re.test(value);         },         "please check input." ); 

and

$("#textbox").rules("add", { regex: "^[a-za-z'.\\s]{1,40}$" }) 

the regex include

^(\d+(?:(?: \d+)*\/\d+)?)$ 

which can seen @ http://regex101.com/r/cb3fq1/2

when enter regex jquery, no entries pass. how entered

$("#textbox").rules("add", { regex: "^(\d+(?:(?: \d+)*\/\d+)?)$" }) 

is because wrapping in string , syntac conflicting? inexperienced @ regex , not sure how go trouble shooting this. please advise me if see error is. thank you.

you need double escape backslashes since you're entering regex string:

$("#textbox").rules("add", { regex: "^(\\d+(?:(?: \\d+)*\/\\d+)?)$" }) 

or else use regex literal:

$("#textbox").rules("add", { regex: /^(\d+(?:(?: \d+)*\/\d+)?)$/ })