Using form values javascript

Question

I'm trying to access form data through a Javascript function when an input is 'changed'. Currently I use something like this:

<form>
    <input type="radio" name="type" name="myValue" onchange="myFunction(this.form)>
</form>

<script>
    function myFunction(form) {
        var value = form.type.value;
    }
</script>

And it works, however instead of writing

var value = form.type.value;

I need to write something like this

var myArray = ["type"];
var value = form.myArray[0].value;

Which is not working. Is this due to how values in arrays are handled?
I have it here on JSFiddle if that is useful.
Thanks

Joseph Young · Accepted Answer · 2016-01-22 21:00:26Z

2

Try

var value = form[myArray[0]].value;

form.myArray[0] is first getting the member myArray from form, and then trying to get the first item in that. Equal to (form.myArray)[0]

form[myArray[0]] explicitly says get the member from form which is of the name of the value inside myArray[0]

answered Jan 22, 2016 at 21:00

Joseph Young

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Comments

madox2 · Accepted Answer · 2016-01-22 21:04:48Z

0

You can access properties of object using [] like this:

var value = form["type"].value;
// equivalent to:
var value = form.type.value

In your case this should work:

var myArray = ["type"];
var value = form[myArray[0]].value;

edited Jan 22, 2016 at 21:04

answered Jan 22, 2016 at 21:00

madox2

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Comments

g.sui · Accepted Answer · 2016-01-22 21:05:44Z

0

'myArray' is declared as a local variable but it is NOT form's property. So form.myArray will fail.

answered Jan 22, 2016 at 21:05

g.sui

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