<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
<style>
li {
list-style: none;
width: 100px;
height: 100px;
background-color: pink;
margin: 5px;
}
</style>
</head>
<body>
<ul>
<li class="box1"></li>
<li class="box2"></li>
<li id="box3"></li>
<li class="box4"></li>
<li class="box5"></li>
</ul>
<script>
var box3 = document.getElementById("box3");
box3.parentNode.style.backgroundColor = "blue";
var pre = box3.previousElementSibling || box3.previousSibling;
var net = box3.nextElementSibling || box3.nextSibling;
pre.style.backgroundColor = "red";
net.style.backgroundColor = "yellow";
var first = box3.parentNode.firstElementChild || box3.parentNode.firstChild;
var last = box3.parentNode.lastElementChild || box3.parentNode.lastChild;
first.style.backgroundColor = "orange";
last.style.backgroundColor = "green";
var arr = box3.parentNode.children;
for(var i=0;i<arr.length;i++){
arr[i].style.backgroundColor = "black";
}
console.log(box3.parentNode.childNodes);
var arr2 = box3.parentNode.childNodes;
for(var i=0;i<arr2.length;i++){
if(arr2[i].nodeType === 1){
console.log(arr2[i]);
}
}
var index = 0;
var node = box3.parentNode.children[index];
function siblings(elm) {
var a = [];
var p = elm.parentNode.children;
for(var i =0;i<p.length;i++) {
if(p[i] !== elm) {
a.push(p[i]);
}
}
return a;
}
</script>
</body>
</html>