PRB: Parseint Returns 0 for Some Strings with Leading Zeros

ID: Q191434

The information in this article applies to:

Microsoft JScript, version 3.0
Microsoft Internet Explorer (Programming) versions 4.0, 4.01, 4.01 SP1, 5.0

SYMPTOMS

When a string value that contains leading zeros is passed to the parseInt() JScript function, parseInt will return 0 for "08" and "09".

CAUSE

In JavaScript placing a leading 0 in front of a number designates that number as octal. In octal, there is no 08 or 09. Therefore, these numbers are interpreted as 0.

RESOLUTION

You must remove the leading zeros before calling parseInt. Here is the code for the workaround:


function parseVal(val)
{
   while (val.charAt(0) == '0')
      val = val.substring(1, val.length);

   return val;
}

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

The following Web page demonstrates this problem. This Web page contains a text box. When focus is shifted away from the edit box by pressing the TAB key, the parseInt() function is called with the value that was entered into the text box. The value returned from parseInt() is then displayed in an alert box. If you enter "08" or "09" into the text box, parseInt() returns a value of 0.


<HTML>
<HEAD>
   <TITLE>Problem with parseInt</TITLE>
</HEAD>
<BODY>
   <INPUT TYPE=TEXT name="TXT1">
   <SCRIPT FOR="TXT1" EVENT=onchange>
      var val = parseInt(TXT1.value);
      alert(val);
   </SCRIPT>
</BODY>
</HTML>

The following JScript code demonstrates the workaround for this problem.


<HTML>
<HEAD>
   <TITLE>THEAD</TITLE>

   <SCRIPT LANGUAGE="JScript">
      function parseVal(val)
      {
         while (val.charAt(0) == '0')
            val = val.substring(1, val.length);

         return val;
      }
   </SCRIPT>
</HEAD>
<BODY>
   <INPUT TYPE=TEXT name="TXT1">
   <SCRIPT FOR="TXT1" EVENT=onchange>
      var val = parseVal(TXT1.value);
      alert(val);
   </SCRIPT>
</BODY>
</HTML>

Additional query words:

Keywords : kbIE400 kbIE401 kbJScript300 kbScript kbIE401sp1 kbIE500
Version : WINDOWS:3.0,4.0,4.01,4.01 SP1,5.0
Platform : WINDOWS
Issue type : kbprb