Selector children « jQuery « JavaScript Tutorial

30.4.Selector children
30.4.2.onlyChild(): If the parent has other child elements, nothing is matched.
30.4.3.Select n-th child
30.4.4.Finds all children of the element with id "main"
30.4.5.Finds all p elements that are children of a div element
30.4.6.Is it the first child
30.4.7.Matches all child elements specified by child of elements specified by parent