linkedList

linkedList.js

const linkedList = {
  toc: {
    children: [
      {id: '1-1', val: '1-1', children: []},
      {
        id: '1-2', 
        val: '1-2',
        children: [
          {id: '2-1', val: '2-1', children: []},
          {id: '2-2', val: '2-2', children: []},
          {id: '2-3', val: '2-3', children: []},
          {
            id: '2-4', 
            val: '2-4',
            children: [
              {id: '3-1', val: '3-1', children: []},
              {
                id: '3-2', 
                val: '3-2',
                children: [
                  {id: '4-1', val: '4-1', children: []},
                  {id: '4-2', val: '4-2', children: []},
                  {id: '4-3', val: '4-3', children: []},
                  {
                    id: '4-4', 
                    val: '4-4',
                    children: [
                      {id: '5-1', val: '5-1', children: []},
                      {id: '5-2', val: '5-2', children: []},
                      {id: '5-3', val: '5-3', children: []},
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
};
var res = [];

function seeker (arr) {
  arr.forEach(function(elem){
    if(elem.children.length) {
      res = elem.children.slice();
      seeker(elem.children);
    }
  })
}

seeker(linkedList.toc.children);
console.log(res);