javascrpit樹（未完）

function traverseDf(data, callback) {
    (function recurse(currentNode) {
      
      if(currentNode.children) {
          for(let item of currentNode.children) {
              recurse(item);
          }
      }
      callback(currentNode);
  })(data);
}

// 廣度優先
function traverseBf(data, callback) {
  const queue = [];
  queue.push(data);
  let currentTree = queue.shift();

  while(currentTree){
      if(currentTree.children) {
          for(const item of currentTree.children) {
              queue.push(item);
          }
      }
      callback(currentTree);
      currentTree = queue.shift();
  }
}

// 獲取樹中某個key的全部value
function getArray(data, key) {
    const vals = [];
    const cb = function cb(node) {
        if(node[key]) {
            vals.push(node[key]);
        }
    }
    traverseBf(data, cb);
    return vals
}

// 給樹中節點添加屬性
function addPropToTree(data, key, callback) {
    const cb = function cb(node) {
        node[key] = callback(node);
    }
    traverseBf(data, cb);
    return data;
}