Dynamically create variable in JavaScript function

Question

I cannot get this to work:

function formvalidation()
{
  var SiteNum= document.getElementsByName("sitesinput")[0].value;           
  var i=1;
  while (i<=SiteNum)
  {
    var SitePhone= document.getElementsByName(site['i'])[0].value;  
    alert(SitePhone);
    i++;
  }
}

If I alert like so: alert('document.getElementsByName(site["'+i+'"])[0].value'); it will display the following:

document.getElementsByName(site["1"])[0].value
document.getElementsByName(site["2"])[0].value
document.getElementsByName(site["3"])[0].value

But I cannot get it to go into a variable.

Thanks for looking, B.

Paulo Santos · Accepted Answer · 2011-06-08 13:51:37Z

1

Try replacing the line

var SitePhone= document.getElementsByName(site['i'])[0].value;

for

var SitePhone= document.getElementsByName(site[i])[0].value;

answered Jun 8, 2011 at 13:51

Paulo Santos

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Comments

Matt Ball · Accepted Answer · 2011-06-08 14:18:18Z

0

Remove the quotes from i. Use a for loop since it fits the use case better than a while loop.

function formvalidation()
{
    var SiteNum= document.getElementsByName("sitesinput")[0].value,
        SitePhone;

    for(var i=1; i<=SiteNum; i++)
    {
        SitePhone = document.getElementsByName(site[i])[0].value;  
        alert(SitePhone);
    }
}

Also, JavaScript does not have block-level scoping, only function-level.

I like this solution, however it wont work without the quotes (") i.e. if do everything the same, but put the name in myself, like ("site[1]") - it will work.

I see where you're headed now.

SitePhone = document.getElementsByName('site[' + i + ']')[0].value;

edited Jun 8, 2011 at 14:18

answered Jun 8, 2011 at 13:55

Matt Ball

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2 Comments

Bifterss Over a year ago

I like this solution, however it wont work without the quotes (") i.e. if do everything the same, but put the name in myself, like ("site[1]") - it will work. Any ideas.

Matt Ball Over a year ago

Oh, so site isn't an array that contains names? See my edit.

shelman · Accepted Answer · 2011-06-08 13:53:38Z

0

You are putting quotes around the i in the line

var SiteNum = document.getElementsByName(site['i'])[0].value

which is looking for the element keyed by the string 'i' instead of the value of the variable i. Try removing the quotes.

answered Jun 8, 2011 at 13:53

shelman

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Comments

BonyT · Accepted Answer · 2011-06-08 13:53:50Z

0

Try

 alert(document.getElementsByName(site[i])[0].value);

answered Jun 8, 2011 at 13:53

BonyT

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