Question

function prev( node ){
    do {
       elem = elem.previousSibling;
    } while( elem && elem.nodeType != 1 );
return elem;
}

In this function we are looking for previous node to a given node. Got this piece of code from John Resig work. This works perfectly I would like have deep understanding of this specifically why he checks elem.nodeType != 1

Somebody pls explain.

Answer 1

nodeType == 1 is an element node.

So this code selects first previous node that is an element.

Full list of node types you can find here.