javascript validation

Question

I am using a regular expression validation to validate my form using javascript. my pattern is

/^[a-zA-Z]+[a-zA-Z0-9_]*\\.{0.1}[a-zA-Z0-9_]*/

is this pattern correct for validating "not starting from number","only 1 '.' allowed and then text"?

wat can i use in javascript for validation?? something like preg_match func of php.

I m not familiar with regular expressions so help me and give sum func to do this for me. i tried to use regexp object but cant get result from .exec,test function.

I'm not quite clear on what you want to achieve with the regular expression, but I advise you to check out regextester.com which I use to verify my "regexes", as well as take a look at regular-expressions.info/reference.html, as there are probably a few character classes, that will make it easier to read your expression — Mallox
– Mallox, Commented Feb 2, 2011 at 11:04

Kissaki · Accepted Answer · 2011-02-02 11:22:07Z

2

Yes, the regexp looks good. Require 1 char, followed by 0..inf char, number or _, followed by an optional dot, followed by 0..inf char, number or _.

You have one syntacticaly error though. Replace the {0.1} with {0,1}.

You can then use the .test() function and pass it a string to test.

var a = "bb";
var r = /^[a-zA-Z][a-zA-Z0-9_]*\.{0,1}[a-zA-Z0-9_]*/;
r.test(a);

returns true.

edited Feb 2, 2011 at 11:22

answered Feb 2, 2011 at 11:04

Kissaki

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3 Comments

Aakash Sahai Over a year ago

hey thanks for your support but..this validation pattern not working perfectly...i used '$' at the end then its working perfectly..May i know what is the use of '$' at the end..i used it eariler but didnt asked y it is used..

Riccardo Galli Over a year ago

the first 'plus' is unnecessary

Kissaki Over a year ago

$ marks the end of a string. Thus, if you include it in your regexp it will require that the string ends there. This is helpful if you want to specify specific lengths as well etc.

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