regular expression issue

Question

i am getting the following regex from a json from server

regexval = ^[A-Za-z\\'\\s\\.\\-\\,]{1,50}$

there is a problem with this regular expression it has a ' which is breaking my js code to test this regular expression. how do i make this a valid regex?

im doing something like this to test it

if(!regexval.replace(/\\/g,"\\").test(inputVal)) {
}

EDIT

following is the JSON

[
    {
        "ExtensionData": {},
        "Data1": null,
        "DisplayName": "First Name",
        "IsRequired": true,
        "LengthValidation": 0,
        "Name": "ServiceFirstName",
        "RegexValidation": "^[A-Za-z\\'\\s\\.\\-\\,]{1,50}$",
        "Type": "String",
        "ValidationMessage": "The field 'First Name' doesn't meet the format requirements"
    },
 {
        "ExtensionData": {},
        "Data1": null,
        "DisplayName": "Last Name",
        "IsRequired": true,
        "LengthValidation": 0,
        "Name": "ServiceLastName",
        "RegexValidation": "^[A-Za-z\\'\\s\\.\\-\\,]{1,50}$",
        "Type": "String",
        "ValidationMessage": "The field 'Last Name' doesn't meet the format requirements"
    }
]

doing \\ in there will just cause your regex to look for literal backslashes (multiple times) and literal ', s, ., -, and , — Marc B
– Marc B, Commented Aug 5, 2011 at 16:38
so how do i make the regex valid? because !regexval.test(inputVal) is not working — Kishore
– Kishore, Commented Aug 5, 2011 at 16:40
is this object that json is passing in a string format to begin with? — Joseph Marikle
– Joseph Marikle, Commented Aug 5, 2011 at 16:44

Rudu · Accepted Answer · 2011-08-05 17:41:45Z

3

The double backslashes are evaluated to literal backslashes in RegEx notation... or escaped backslashes in a string (which then escapes the next character when evaluated as a regex).

The RegEx build solution is:

regexval=/^[A-Za-z\'\s\.\-\,]{1,50}$/

The string-build solution is:

regexval = new RegExp("^[A-Za-z\\'\\s\\.\\-\\,]{1,50}$");

Both of these produce a JavaScript RegEx object which you can then call .test etc on.

if (regexval.test(inputVal)) {
  //... do something
}

Your Update

Ok so per your update, if you parse that above structure into a local JS object called jsonobj (for example... how to parse etc I assume you know) and you want to just test the first entry in the JSON array returned... you'd need to do the following:

//jsonobj - JS object after parsing your example JSON above
var regex=new RegEx(jsonobj[0].RegexValidation);
if (regex.test(inputVal)) {
    //... do your work here
}

edited Aug 5, 2011 at 17:41

answered Aug 5, 2011 at 16:44

Rudu

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1 Comment

Kishore Over a year ago

but still ^[A-Za-z\'\s\.\-\,]{1,50}$ is breaking i guess because of the ' what should i do? it says regexval.test is not a function

Mark Schultheiss · Accepted Answer · 2011-08-05 19:03:45Z

1

Can you change the single quote to a unicode character /u0027 or use the ASCII \x27 and have it work properly?

See it in action here: http://jsfiddle.net/TezdR/1/

SO, really you DON'T need to do the replace but can use the "string" as it is - here is an updated version where you can see I do the replace on FirstName but not on last - and they both should work the same: http://jsfiddle.net/TezdR/2/

edited Aug 5, 2011 at 19:03

answered Aug 5, 2011 at 17:08

Mark Schultheiss

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1 Comment

Kishore Over a year ago

how do i change it all i have is the json from the webservice

Joseph Marikle · Accepted Answer · 2011-08-05 16:43:02Z

1

regexval = /^[A-Za-z\\'\\s\\.\\-\\,]{1,50}$/

you're missing the /s needed to make it a regex value

and it looks like you actually need

regexval = /^[A-Za-z\'\s\.\-\,]{1,50}$/

answered Aug 5, 2011 at 16:43

Joseph Marikle

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