深度优先查询、广度优先查询、扁平化数组变成树

深度优先查询、广度优先查询、扁平化数组变成树

深度广度数据

const arr = [
        {
          id: 1,
          label: "一级 1",
          children: [
            {
              id: 4,
              label: "二级 1-1",
              children: [
                {
                  id: 9,
                  label: "三级 1-1-1",
                },
              ],
            },
          ],
        },
        {
          id: 2,
          label: "一级 2",
          children: [
            {
              id: 5,
              label: "二级 2-1",
              children: [
                {
                  id: 10,
                  label: "三级 2-1-1",
                },
              ],
            },
            {
              id: 6,
              label: "二级 2-2",
              children: [
                {
                  id: 11,
                  label: "三级 2-2-1",
                },
              ],
            },
          ],
        },
        {
          id: 3,
          label: "一级 3",
          children: [
            {
              id: 7,
              label: "二级 3-1",
              children: [
                {
                  id: 12,
                  label: "三级 3-1-1",
                },
              ],
            },
            {
              id: 8,
              label: "二级 3-2",
              children: [
                {
                  id: 13,
                  label: "三级 3-2-1",
                },
              ],
            },
          ],
        },
      ];

深度优先查询

 const id = 9;
      function shendu(currentTree) {
        for (let i = 0; i < currentTree.length; i++) {
          if (currentTree[i].id !== id) {
            if (currentTree[i].children) {
              shendu(currentTree[i].children);
            }
          } else {
            console.log(currentTree[i]);
            break;
          }
        }
      }
      shendu(arr);

广度优先查询

 function guangdu() {
        let current;
        const queue = [...arr];
        for (let i = 0; i < queue.length; i++) {
          current = queue[i];
          if (current.id !== 9) {
            if (current.children) {
              queue.push(...current.children);
            }
          } else {
            break;
          }
        }
        console.log(current);
      }

扁平化数组变成树

const list: [
      { pid: -1, name: "购物车", id: 1, auth: "cart" },
      { pid: 1, name: "购物车列表", id: 4, auth: "cart-list" },
      { pid: 4, name: "**", id: 5, auth: "lottery" },
      { pid: 4, name: "商品", id: 6, auth: "product" },
      { pid: -1, name: "商店", id: 2, auth: "shop" },
      { pid: -1, name: "个人中心", id: 3, auth: "store" },
    ], 
const getTree = (tree) => {
        const newList = [];
        for (let i = 0; i < tree.length; i++) {
          if (tree[i].pid === -1) {
            newList.push(tree[i]);
          } else {
            const findItem = tree.find((item) => item.id === tree[i].pid);
            if (findItem) {
              if (findItem.children) {
                // 更改原数组就相当于给新数组里面添加了children，因为新数组里面元素的地址和原数组是一个、
                findItem.children.push(tree[i]);
              } else {
                findItem.children = [tree[i]];
              }
            }
          }
        }
        return newList;
      };
getTree(arr)