Getting a single element with `getElementsByTagName`

javascript html dom getelementsbytagname
Jamna picture Jamna · Jul 21, 2011 · Viewed 17.7k times · Source

I know that if we want to find a group of elements, getElementsByTagName is the method for us and it returns a NodeList. but if we are looking for tag name with "body" , then why we need to add [0] after the ("body") element? There is only one body tag in an HTML document.

 var body = document.getElementsByTagName("body")[0];
 body.className = "unreadable";

why we cant write this code without index[0] like this

 var body = document.getElementsByTagName("body");
 body.className = "unreadable";

If i write this code the class unreadable will not be added with body tag ...why?

Answer

Molecular Man picture Molecular Man · Jul 21, 2011

Because document.getElementsByTagName allways returns NodeList. If you want find easier way to retrieve body you can use just document.body

Related questions

How can I change an element's class with JavaScript?

How can I change the class of an HTML element in response to an onclick or any other events using JavaScript?

Read More
How to make JavaScript execute after page load?

I'm executing an external script, using a <script> inside <head>. Now since the script executes before the page has loaded, I can't access the <body>, among other things. I'd like to execute some JavaScript …

Read More
How can I select an element by name with jQuery?

Have a table column I'm trying to expand and hide: jQuery seems to hide the td elements when I select it by class but not by element's name. For example, why does: $(".bold").hide(); // selecting by class works $("tcol1").hide(); // …

Read More