Print tree node list, generate structure string and find childrens

tree.js

const nodes = [
  { id: 1 },
  { id: 2, pid: 1 },
  { id: 3, pid: 1 },
  { id: 4, pid: 2 },
  { id: 5, pid: 2 },
  { id: 6, pid: 3 },
  { id: 7, pid: 3 },
  { id: 8, pid: 3 },
]

const getChildrenIds = (parentId, all) => {
  let result = []
  for (key in all) {
    let node = all[key];
    if (node.pid === parentId) {
      result.push(node.id)
      const childrenIds = getChildrenIds(node.id, all)
      if (childrenIds.length !== 0) {
        result.push(...childrenIds)
      }
    }
  }
  return result // children id
}

const getStruct = (id, all) => {
  const target = all.filter(node => node.id === id)[0]
  if (target.pid) {
    return getStruct(target.pid, all) + '/' + id
  }
  return target.id
}

const printNode = (id, all) => {
  const childrenIds = getChildrenIds(id, all);
  for (const key in childrenIds) {
    const node = all[key]
    const struct = getStruct(node.id, all)
    console.log(`id: ${node.id}\t struct:${struct}`);
  }
}

console.log("Children:", getChildrenIds(1, nodes))
console.log("Structure:", getStruct(5, nodes))
printNode(1, nodes)