How to get nodes such as brothers and parent classes in js_javascript skills

var chils= s.childNodes; //Get all the child nodes of s

var par=s.parentNode; //Get the parent node of s

var ns=s.nextSbiling; // Get the next sibling node of s

var ps=s.previousSbiling; //Get the previous sibling node of s

var fc=s.firstChild; //Get the first one of s Child node

var lc=s.lastChile; //Get the last child node of s