GetElementsByTagName fails although getElementById works

Question

The following script works perfectly, but when I try it with GetElementsByTagName it fails. An ID can only be used once and I want to use it for ('a', h1, h2).

Thoughts, ideas or solutions are welcome.

window.setInterval(function(){
    var t = document.getElementById('test');  
    var z = 'rgb('+ (Math.floor(Math.random() * 184)) + ',' 
                  + (Math.floor(Math.random() * 102)) + ',' 
                  + (Math.floor(Math.random() * 184)) + ')';                    
    t.style.color = z
}, 1000);

Show the code that *doesn't* work. We can't tell how to fix the code that already works. — JJJ, Sep 07 '17 at 06:34

Manoj Pilania · Accepted Answer · 2017-09-07T07:10:51.263

0

getElementById return only single element but getElementsByTagName return array. You can use this code.

window.setInterval(function(){
var t = document.getElementsByTagName('h1');  
var z = 'rgb(' + (Math.floor(Math.random() * 184)) + ',' 
                 + (Math.floor(Math.random() * 102)) + ',' 
                     + (Math.floor(Math.random() * 184)) + ')';
for(var i=0;i < t.length; i++)
{
  t[i].style.color = z
}

}, 1000);

edited Sep 07 '17 at 07:10

answered Sep 07 '17 at 06:42

Manoj Pilania

664
1
7
18

1

Don't use a `for in` loop to iterate over `t`. `console.log(i)` will show you it also will iterate over the `length`, `item` and `namedItem` properties. – Cerbrus Sep 07 '17 at 06:56
Yes you are right @Cerbrus, I edited the answer. – Manoj Pilania Sep 07 '17 at 07:11
Perfect! Adding in the for loop fixed it!! – Hendrik Eduard Kuiper Sep 07 '17 at 10:03

GetElementsByTagName fails although getElementById works

1 Answers1