原生JS找节点的兄弟姐妹

<div class="parent">
  <div class="a"></div>
  <div class="b"></div>
  <div class="c"></div>
</div>

let children = document.querySelector('.parent').childNodes
console.log(children)
let array = []
for(let i=0;i<children.length;i++){
  if(children[i].nodeType === 1 && children[i].className !== "a"){
    array.push(children[i])
  }
}
//找到了a的兄弟节点

思路：找出父节点，再找出所有子节点，for循环除去自己和多余的空格节点