CODEWITHSUNDEEP
javascripthtml
Jitender
Jitender

Reputation: 7971

javascript loop not working?

i want to know length of a tags

<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>Untitled Document</title>
  <script type="text/javascript">
    function clickme(){
      var x=document.getElementsByTagName('a');
      for(i=0;i<x.length;i++) {
        alert(x[i].length)
      }
    }
</script>
</head>
<body>
  <a href="#" value="1">first</a>
  <a href="#" value="2">second</a>
  <a href="#" value="3">third</a>
  <input type="submit"  onclick="clickme()"/>
</body>

Upvotes: 1

Views: 104

Answers (4)

webnesto
webnesto

Reputation: 1319

I'm confused, you've changed your original question code sample from:

<script type="text/javascript">
    function clickme(){
      var x=document.getElementsByTagName('a');
      for(i=0;i<x.length;i++) {
        alert(x[i].value) //<- "value" not a valid property on the anchor tag
      }
    }
</script>

to

<script type="text/javascript">
    function clickme(){
      var x=document.getElementsByTagName('a');
      for(i=0;i<x.length;i++) {
        alert(x[i].length) //<- "length" not a valid property on the anchor tag
      }
    }
</script>

If you're just trying to determine what the ordered number of that anchor tag itself is, you could just use "i" (and again - var it!):

<script type="text/javascript">
    function clickme(){
      var x=document.getElementsByTagName('a');
      for( var i=0;i<x.length;i++) {
        alert(i);
      }
    }
</script>

Or am I missing something that you're asking?

Upvotes: 1

webnesto
webnesto

Reputation: 1319

jfriend00 got that right.

I thought I'd also point out though that you might want to declare "i" either ahead of, or inline with your for. Otherwise you're using a global "i" that could have unexpected consequences elsewhere.

Upvotes: 1

mjc
mjc

Reputation: 3426

In this example, x[i] is a anchor DOM Element object. It doesn't have a value property normally. However, if you want to use the property, you can access it via:

x[i].getAttribute('value');

Personally, I would use HTML5 data attributes and define the anchor like:

<a href="#" data-value"=1">one</a>

Then access the value via:

x[i].getAttribute('data-value');

If a HTML5 doctype is used, this will be valid.

Upvotes: 2

jfriend00
jfriend00

Reputation: 707328

Since value is not a standard property of a link, you will probably need to use .getAttribute("value"):

var x = document.getElementsByTagName('a');

for (var i=0; i<x.length;i++){
    alert(x[i].getAttribute("value"));
}

Upvotes: 5

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