如何将特定的 Json 部分作为独立对象返回？

Question

I have Json object as shown below:

{
  id : 0,
  cnt: 1,
  someStuff : 'lalala',
  1: {
    id : 1,
    cnt: 2,
    someStuff : 'allgood',
    1: {
      id : 2,
      cnt: 0,
      someStuff: 'nice'
    },
    2: {
      id : 3,
      cnt : 0,
      someStuff: 'nice2'
    }
  }
}

And all I want to do is to return some part of this Json as independent object. If Im using this function :

function CurrentNodeReturn(obj, idReturn) {
    if (idReturn == 0) { return obj; }
    for (var i = 1; i < obj.cnt + 1; i++) {
        if (obj[i].id == idReturn) {
            return obj[i];
        } else {
            return CurrentNodeReturn(obj[i], idReturn);
        }
    }
}

I can get the same object I send with Id =0. Also I can get separated object wit ids 1 and 2. But when I need to get object with id = 3 all i get is "undefined" errors in console log. So how can I improve my function's alghoritm if every time I call CurrentNodeReturn function with parameters (all main object I mentioned, node's id which should be returned to starting call point)?

Answer 1

How can I improve my function's alghoritm if every time I call CurrentNodeReturn function with parameters?

First, you should change your stopping condition to check if the id maches or if the object is undefined.

Otherwise, if you do not meet the stop condition, loop over the children and call your function recursively and return the value if it is not undefined .

 const data = { id : 0, cnt: 1, someStuff: 'lalala', 1: { id : 1, cnt: 2, someStuff: 'allgood', 1: { id : 2, cnt: 0, someStuff: 'nice' }, 2: { id : 3, cnt : 0, someStuff: 'nice2' } } }; function getObject(obj, id) { if (!obj || obj.id === id) { return obj; } for (let i = 0; i < obj.cnt; i++) { const child = getObject(obj[i + 1], id); if (child) { return child; } } } console.log(getObject(data, 2)) console.log(getObject(data, 3))