Add class to first child using javascript

Question

is there any reason this chain does not work? It does not add the class:

document.getElementsByTagName(\'nav\')[0].firstChild.className = \"current\"
         


        

Answer 1

The statement:

document.getElementsByTagName('nav')[0].firstChild.className = "current"

is somewhat fragile as any change in the assumed document structure breaks your code. So more robust do do something like:

var links, 
    navs = document.getElementsByTagName('nav');

if (navs) links = nav[0].getElementsByTagName('a');

if (links) links[0].className = links[0].className + ' ' + 'current';

You should also have robust addClassName and removeClassName functions.