GeekInterview.com
   Home |  Tech FAQ  |   Interview Questions |  Placement Papers |  Tech Articles |  Learn |  Freelance Projects |  Online Testing |  Geeks Talk |  Job Postings |  Knowledge Base | Site Search |  Add/Ask Question

GeekInterview.com  >  Interview Questions  >  Web  >  java Script
Next Question 
 java Script  |  Question 1 of 23    Print  
How to use email validation in Java script.Like User can't enter invalid email address?

  
Total Answers and Comments: 5 Last Update: May 03, 2007     Asked by: mrbaliram 
  
 Sponsored Links

 
 Best Rated Answer
Submitted by: vinod_arya
 

u have basically 2 search occurance of @ symbol and at least 2 "."(period) signs in the mail id which u can search using String functions



Above answer was rated as good by the following members:
malkaps
February 02, 2006 07:32:35   #1  
bicu Member Since: September 2005   Contribution: 21    

RE: how i will use email validation in java script,

First of all, here is the javascript function that tests if an email address is valid.
It checks for a lot of things: to see if the email contains a "@" sign and a dot, checks to see if the @ is before the dot, and so on.

<script>
function isMail(str)
{
   var at="@";
   var dot=".";
   var lat=str.indexOf(at);
   var lstr=str.length;
   var ldot=str.indexOf(dot);
   if (str.indexOf(at)==-1) return false;
   if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr) return false;
   if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr) return false;
   if (str.indexOf(at,(lat+1))!=-1) return false; if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot) return false;
   if (str.indexOf(dot,(lat+2))==-1) return false;
   if (str.indexOf(" ")!=-1) return false;
   return true;
}

// the next function will be used to validate the form. I made this as a separate function because you might want to validate more fields.
function validate_form()
{
   if (!isMail(document.form1.mail.value))
   {
      alert("Please enter a valid email address");
      document.form1.mail.focus();
      return false;
   }
   // if the value entered is not a valid email address, 
   // we show a message, focus on the field and return false.
   // returning false will make sure the form is not submitted

   // if we got here, it means the email address is valid
   return true;
   // return true means that the form is submitted.
}

</script>

After placing this function in the code, here is what you need to put in the form.

Let's say the form only has the email address and a submit button.

<form action="/" method="post" onsubmit="return validate_form()" name="form1">
<input type="text" name="email" value="">
<input type="submit" name="submit_button" value="continue">
</form>


 
Is this answer useful? Yes | NoAnswer is useful 1   Answer is not useful 0Overall Rating: +1    
February 26, 2006 09:27:01   #2  
vinod_arya Member Since: September 2005   Contribution: 6    

RE: how i will use email validation in java script,

u have basically 2 search occurance of @ symbol and at least 2 "."(period) signs in the mail id which u can search using String functions


 
Is this answer useful? Yes | NoAnswer is useful 1   Answer is not useful 0Overall Rating: +1    
August 06, 2006 23:27:01   #3  
michael        

RE: how i will use email validation in java script,
a better way is to use regular expression
 
Is this answer useful? Yes | NoAnswer is useful 1   Answer is not useful 0Overall Rating: +1    
December 06, 2006 10:25:56   #4  
toneerajkumar Member Since: October 2005   Contribution: 1    

RE: How to use email validation in Java script.Like Us...
script for email validations// check if email field is blankif (theForm.Email.value == ""){alert("Please enter a value for the "Email" field.");theForm.Email.focus();return (false);}// test if valid email address, must have @ and .var checkEmail = "@.";var checkStr = theForm.Email.value;var EmailValid = false;var EmailAt = false;var EmailPeriod = false;for (i = 0; i < checkStr.length; i++){ch = checkStr.charAt(i);for (j = 0; j < checkEmail.length; j++){if (ch == checkEmail.charAt(j) && ch == "@")EmailAt = true;if (ch == checkEmail.charAt(j) && ch == ".")EmailPeriod = true; if (EmailAt && EmailPeriod) break; if (j == checkEmail.length) break; } // if both the @ and . were in the stringif (EmailAt && EmailPeriod){ EmailValid = true break; }}if (!EmailValid){alert("The "email" field must contain an "@" and a ".".");theForm.Email.focus();return (false);}
 
Is this answer useful? Yes | NoAnswer is useful 1   Answer is not useful 0Overall Rating: +1    
May 03, 2007 07:24:40   #5  
Saurabh        

RE: How to use email validation in Java script.Like Us...
/^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$/

Use this regular expression

You can be more strict by using .com,.biz,.org,.arpa etc in regular expression

 
Is this answer useful? Yes | NoAnswer is useful 1   Answer is not useful 0Overall Rating: +1    


 
Go To Top


 Sponsored Links

 
Sponsored Links

 




About Us  |   Privacy Policy  |   Terms and Conditions  |   Contact  |   Site Map  |   Add Question  |   Propose Category  |   RSS Feeds  |   Articles Sitemap  |   Site Updates  |   Add Resource

Copyright © 2005 - 2008 GeekInterview.com. All Rights Reserved
Page copy protected against web site content infringement by Copyscape