JavaScript Function to check numeric not working?

[JohnBates]

Hello JS experts -

I am trying to validate what has been entered into text boxes.... to be certain the user entered all numeric characters.

My Problem:
When I enter non-numeric characters, the isNum function is not detecting this (don't get the alert message in the ValidateInput function). Do I have an error in my code?

Thanks, John

Here is my code:


<SCRIPT language=&quot;JavaScript&quot;>
<!--
function ValidateInput()
{

if (!isNum(frmUser.Dept.value))
{
alert (&quot;Please enter your Department number - all digits&quot
frmUser.Dept.focus()
return false
}


if (!isNum(frmUser.PhoneW.value))
{
alert (&quot;Please enter your work phone number&quot
frmUser.PhoneW.focus()
return false
}

return true

}

// Is the entered value a Number ?
function isNum(entry)
{

alert (&quot;In isNum...value of number box is &quot;+ entry)
if (entry == &quot;&quot
{
return false

}

for (i=0; i<entry.length; i++)
{
if (entry.charat(i) < &quot;0&quot; )
{
return false
}
if (entry.charat(i) > &quot;9&quot; )
{
return false
}
}
return true
}
-->
</SCRIPT>

 

[DJSmith]

function isNum(str){
if (str.length == 0)
{
return false;
}
for (var i=0;i < str.length;i++)
{
if ((str.substring(i,i+1) < '0') || (str.substring(i,i+1) > '9'))
{
return false;
}
}
return true;
}//end isNum

try this

 

[Zindagi]

Hi!
To check the the entered text is integer or not you can also use isNaN() just like this:::

function checkIt()
{
var aStr = frmUser.PhoneW.value
if(isNaN(aStr))
{
alert(&quot;Please enter a integer value for telephone.&quot
frmUser.PhoneW.focus()
return false
}
}

Harsh.

 

[Zindagi]

Hi!

isNaN() method will return false if entered text is Integer or float(contains decimal).

But if you want to take only Integer values then firstly check with isNaN() then again check for indexOf(&quot;.&quot if it return -1 then entered text is Integer else not.
Like this::::

function checkIt()
{
var aStr = frmUser.PhoneW.value
if(isNaN(aStr))
{
if(aStr.indexOf(&quot;.&quot != -1)
{
alert(&quot;Please enter integer value for telephone.&quot
frmUser.PhoneW.focus()
return false
}
}
return true
}
Harsh.