Getting form element names in a loop

crapanz · January 28th, 2006, 05:51 AM

I've some Javascript code to iterate through the form elemenets and get their names.
I am wanting to get all the names of unique radio groups and then later test them for a value <> -99.

IF I do this
    vfrmElements = document.question.elements;
    vinNumElements = vfrmElements.length;

    vtxOutput = vfrmElements[0].name + ", " + vfrmElements[1].name + vfrmElements[7].name;

    alert ("Collected Array is " + vtxOutput);
IT WORKS FINE:
HOWEVER when I iterate through the loop of elements and access the elements with the square brackets and integer [i], it doesn't work!
I get undefined, or no properties.
I tried lots of things, but don't get what I want.
I don't get why [i] doesn't work, but [0] ... [71] will work?

    for (i=0; i<= vinNumElements; i++) {
        vfrmElement = vfrmElements[i];
        vtxOutput = vtxOutput + vfrmElement.name + ", "; // This line produces an Error.

    }
    alert ("alert Elements are :" + vtxOutput);
    alert ("Finished loadarray");

Database Agreements

joefawcett · January 28th, 2006, 06:42 AM

As you don't state the error I'm guessing that it's "... is null or not an object" or the like. You are setting the upper limit of the loop too high as the loop index, "i", should be less than the length of the array not equal to it. I would also use getElementsByName for radio buttons so the have the code as:

Code:

var colRadioGroup = document.getElementsByName("myGroup");
var sValues = "";
for (var i = 0; i < colRadioGroup.length; i++)
{
  if (i != 0) sValues += ", "; 
  sValues += colRadioGroup[i].value;
}
alert(sValues);

--

Joe (Microsoft MVP - XML)

crapanz · January 28th, 2006, 12:37 PM

Joe,
I don't have the radio group names before hand.
I'm just testing it out as if I have the radio group namein this Javascript code to see how to write the code to find those names, i.e. proove that I can access them, then store their names in an array for later checking the value of each group.

The loop iteration is a minor problem, its fixed.

The point is document.question.element["rfs1"] works
but when I iterate through the elements it doesn't.

Must be a way to do this.
The error is merely that if I reference the name property, it says that the element has no properties. This is just within the loop.

I'm obviously doing something wrong.
What else can it be, would the id names of the <input type="radio"
elements make a difference. They are different.

Hope this makes sense.

Database Agreements

joefawcett · January 28th, 2006, 12:42 PM

What error do you get?
What does the HTML look like?

--

Joe (Microsoft MVP - XML)

crapanz · January 28th, 2006, 01:09 PM

Joe,
It indeed was the variable loop maximum.
This didn't make sense to me, because of previous output.
I always think when I'm writing Javascript I have to go so slowly.

Now, I want to put the element names in an array passed to this function. This function is run with the onload event.
Then the array is accessed again with the submit click.

I tried this:
varQuest[varQuest.length] = vtxRadioName;
but the error is "the array has no properties."
Can you suggest what is going on?

I'm trying the associative route now.
varQuest[vtxRadioName] = false;

Then I think I'll look at all the keys in this array in the submit event and see if the radio button is checked.

Your code document.getElementsByName["name"] should then work perfectly.

Thanks.

Database Agreements

vinod_yadav1919 · January 30th, 2006, 12:45 AM

Hii crapanz!!
  vfrmElements = document.question.elements;
    vinNumElements = vfrmElements.length;
here vinNumElements is the total number of elements if say 6 then starting index is started from 0 based ,so your code work fine till
vfrmElements[0], vfrmElements[1], vfrmElements[2], vfrmElements[3], vfrmElements[4], vfrmElements[5]
your code will work with
  for (i=0; i<vinNumElements; i++) {
        vfrmElement = vfrmElements[i];
        vtxOutput = vtxOutput + vfrmElement.name + ", "; // This line produces an Error.

    }

Note for (i=0; i<= vinNumElements; i++) is changed
     with --->for (i=0; i<vinNumElements; i++)

Hope this will help you

Cheers :)

vinod