默認代碼 ?

function get_previousSibling(n){
??????? var x=n.previousSibling;
??????? while (x && x.nodeType!=1){
??????????? x=x.previousSibling;
??????? }
??????? return x;
??? }
?? ?
??? var x=document.getElementsByTagName("li")[4];
??? document.write(x.nodeName);
??? document.write(" = ");
??? document.write(x.innerHTML);
?? ?
??? var y=get_previousSibling(x);
?? ?
??? if(y!=null){
??????? document.write("<br />nextsibling: ");
??????? document.write(y.nodeName);
??????? document.write(" = ");
??????? document.write(y.innerHTML);
??? }else{
????? document.write("<br>已經是最后一個節點");???? ?
??? }

我的代碼

?? function get_previousSibing(m){
??????? var z=m.previousSibing;
??????? while(z && z.nodeType!=1){
??????????? z=z.previousSibing;
??????? }
??????? return z;
??? }
??? var z=document.getElementsByTagName("li")[2];
??? document.write("<br><br>")
??? document.write(z.nodeName+"="+z.innerHTML);
?? ?
??? var d=get_previousSibing(z);
??? if(d!=null)
??? {
??? document.write("<br? />previoussibling:"+d.nodeName+" = "+d.innerHTML);
??? }
??? else {
??? document.write("<br>已經是最后一個節點");
??? }
???