递归函数调用返回

Question

I'm iterating over a potentially infinitely-nested JSON recursively.

This is the function I use to do this:

  function iterate(obj,matchId) {
      for(var key in obj) {
          var elem = obj[key];

          if(obj.id == matchId) { //if objects id matches the arg I return it
            console.log(obj); // matched obj is always logged
            return(obj);
          }

          if(typeof elem === "object") { // is an object (plain object or array),
                                         // so contains children
              iterate(elem,matchId); // call recursively
          }
      }
  }

And this is how I call it:

var matchedObj = iterate(json,3);

However, matchedObj get's value undefined since the return value usually comes from calling iterate() from within itself and not directly by var matchedObj = iterate(json,3);

---

Only way I can see now is to use a callback from within the recursive function to perform whatever action I want to do. Is there any other way I'm missing?

---

In any case, this is my JSON:

var json =  [

    {
        "id": 1,
        "text": "Boeing",
        "children": [
            {
                "id": 2,
                "text": "747-300",
                "json": "737 JSON"
            },
            {
                "id": 3,
                "text": "737-400",
                "json": "737 JSON"
            }
        ]
    },
    {
        "id": 4,
        "text": "Airbus",
        "children": [
            {
                "id": 5,
                "text": "A320",
                "json": "A320 JSON"
            },
            {
                "id": 6,
                "text": "A380",
                "json": "A380 JSON"
            }
        ]
    }

]

Answer 1

You just need to return the recursive call if it found the result.

function iterate(obj,matchId) {
      for(var key in obj) {
          var elem = obj[key];

          if(obj.id == matchId) { //if objects id matches the arg I return it
            console.log(obj); // matched obj is always logged
            return(obj);
          }

          if(typeof elem === "object") { // is an object (plain object or array),
                                         // so contains children
              var res = iterate(elem,matchId); // call recursively
              if (res !== undefined) {
                return res;
              }
          }
      }
  }