JavaScript: Guess data type from string

Question

I am looking for a function that can tell me to which data type a string might be converted. Examples:

"28.98" results in float (. as separator)

"44.332,95" results in float (, as separator)

"29/04/14" results in date (should work internationally -> different date formats)

"34.524" results in int (. as delimited)

"all the rest" results in string

Ideally also (these are subclasses of string):

"[email protected]" results in e-mail

"+49/2234/234567" results in phone

Is there a (open source) libary can can do such thing?

Thanks!

Answer 1

There you have it. Not a library, unhealthy amount of regular expressions, but it works with your examples. If you need other things to be matched, please add more examples. Open to critique or requirements in the comments.

function getType(str){
    if (typeof str !== 'string') str = str.toString();
    var nan = isNaN(Number(str));
    var isfloat = /^\d*(\.|,)\d*$/;
    var commaFloat = /^(\d{0,3}(,)?)+\.\d*$/;
    var dotFloat = /^(\d{0,3}(\.)?)+,\d*$/;
    var date = /^\d{0,4}(\.|\/)\d{0,4}(\.|\/)\d{0,4}$/;
    var email = /^[A-za-z0-9._-]*@[A-za-z0-9_-]*\.[A-Za-z0-9.]*$/;
    var phone = /^\+\d{2}\/\d{4}\/\d{6}$/g;
    if (!nan){
        if (parseFloat(str) === parseInt(str)) return "integer";
        else return "float";
    }
    else if (isfloat.test(str) || commaFloat.test(str) || dotFloat.test(str)) return "float";
    else if (date.test(str)) return "date";
    else {
        if (email.test(str)) return "e-mail";
        else if (phone.test(str)) return "phone";
        else return "string";
    }
}