Solved

Trouble with isAlphaNumeric() function

Posted on 2008-10-24
5
478 Views
Last Modified: 2012-06-21
I have a problem with this function but can not yet debug into JavaScript.  Can anyone find the problem?

It does not seem to matter what characters I enter to the text field, the isAlphaNumeric() function seems to always return true.

newbieweb

    function isAlphaNumeric(str){
        return /^[a-zA-Z0-9]+$/.test(str);
    }

    function CheckSize()
    {
        var elem = document.getElementById("recordLocatorTextBox");
        if (elem != null)
        {
            if (!isAlphaNumeric(elem.Value))
            {
                  // it never gets here...
            }
        }
    }
0
Comment
Question by:newbieweb
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 20

Accepted Solution

by:
chaitu chaitu earned 200 total points
ID: 22801933
function isAlphanumeric(elem, helperMsg){
      var alphaExp = /^[0-9a-zA-Z]+$/;
      if(elem.value.match(alphaExp)){
            return true;
      }else{
            alert(helperMsg);
            elem.focus();
            return false;
      }
}
0
 
LVL 4

Assisted Solution

by:sijishJohn
sijishJohn earned 200 total points
ID: 22801935
try this...
function CheckSize()
    {
        var elem = document.getElementById("recordLocatorTextBox");
        if (elem != null)
        {
            if (!isAlphaNumeric(elem.value))
            {
                  // it never gets here...
            }
        }
    }

Open in new window

0
 
LVL 20

Expert Comment

by:chaitu chaitu
ID: 22801937
this also works;

function isAlphaNumeric(val)
{
if (val.match(/^[a-zA-Z0-9]+$/))
{
return true;
}
else
{
return false;
}
}
0
 
LVL 4

Expert Comment

by:sijishJohn
ID: 22801940
change 'isAlphaNumeric(elem.Value)' to isAlphaNumeric(elem.value)
0
 
LVL 42

Assisted Solution

by:David S.
David S. earned 100 total points
ID: 22801984
As sijishJohn said, the isAlphaNumeric function is fine. The problem is the argument passed to it. "elem" does not have a "Value" property, but it doesn't have a "value" property.

The RegExp.test() method is more efficient than the String.match() method.
0

Featured Post

What Is Transaction Monitoring and who needs it?

Synthetic Transaction Monitoring that you need for the day to day, which ensures your business website keeps running optimally, and that there is no downtime to impact your customer experience.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article will give core knowledge of JavaScript and will head in to your first JavaScript program. I am Durvesh Naik and I am here to deal with this series of JavaScript. I will teach you JavaScript in part wise , as its quite boring to read big…
Today, the web development industry is booming, and many people consider it to be their vocation. The question you may be asking yourself is – how do I become a web developer?
The viewer will learn the basics of jQuery, including how to invoke it on a web page. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery.: (CODE)
The viewer will learn the basics of jQuery including how to code hide show and toggles. Reference your jQuery libraries: (CODE) Include your new external js/jQuery file: (CODE) Write your first lines of code to setup your site for jQuery…

705 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question