Using a variable in a DOM string

Question

I am trying to put a variable into a dom string. I have various fields as such:

<input type="text" name="itemdesc1" />
<input type="text" name="itemdesc2" />

I want to loop through these to see if they are populated before submit. The only problem I have is that I cannot run them through a loop, because I need to put a variable into the DOM string. The variable is "i".

if (document.insertinv.itemdesc(variable_here).value == ''){
     // Code
}

Is there any specific way to do this? Preferably without adding id's to the fields.

Thanks!

Christian C. Salvadó · Accepted Answer · 2010-01-06 04:48:28Z

3

You can use the bracket notation, also I would encourage you to access your form elements in the standard way, accessing the elements HTMLCollection (document.forms[x].elements[y]):

var element = document.forms[0].elements['itemdesc' + i]; 
         //or document.forms['formName']...
if (element.value == ''){
  // Code
}

answered Jan 6, 2010 at 4:48

Christian C. Salvadó

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Comments

Sampson · Accepted Answer · 2010-01-06 04:48:31Z

2

You'll need to concatenate the variable onto the dom-string:

var elems = document.getElementsByName('itemdesc'+i);

answered Jan 6, 2010 at 4:48

Sampson

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Comments

Treby · Accepted Answer · 2010-01-06 05:11:20Z

1

try

if ( document.getElementsByName("itemdesc"+i).value == '' ){
     //CODE
}

edited Jan 6, 2010 at 5:11

answered Jan 6, 2010 at 4:46

Treby

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4 Comments

Justin Johnson Over a year ago

. is not the concatenation operator

Sampson Over a year ago

Treby is likely a PHP programmer :) I find myself mixing up the syntax from time to time too :)

Treby Over a year ago

sorry man.. got carried away.. yah jonathan.. i am a php programmer

bobince Over a year ago

Nearly there but getElementsByName returns a list of matching elements, not a single element.

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