如何停止此递归函数？

debugcn 发表于 Dev

我有一个javascript数组，其中每个项目都有对父项的引用，并且它们可以循环（循环引用）。例子：

[
        {"id": 1, "firstName": "Macko","parentId": 12},
        {"id": 2, "firstName": "Jess","parentId": 1},
        {"id": 3, "firstName": "Peter","parentId": 1},
        {"id": 4, "firstName": "Lisa", "parentId": 1},
        {"id": 5, "firstName": "Megan","parentId": 1},
        {"id": 6, "firstName": "John", "parentId": 4},
        {"id": 7, "firstName": "Joe", "parentId": 4},
        {"id": 8, "firstName": "Matthew","parentId": 2},
        {"id": 9, "firstName": "Peter","parentId": 2},
        {"id": 10, "firstName": "Dio","parentId": 5},
        {"id": 11, "firstName": "Hello","parentId": 5},
        {"id": 12, "firstName": "Ana", "parentId": 4}
]

我需要创建基于所选记录嵌套数据结构在DOM，我通过递归函数像下面实现，以显示它（源此处）

function getNestedChildren(arr, parent) {
  var out = []
  for(var i in arr) {
    if(arr[i].parent == parent) {
        var children = getNestedChildren(arr, arr[i].id)

        if(children.length) {
            arr[i].children = children
        }
        out.push(arr[i])
    }
  }
  return out
}

它确实运行良好，但不适用于循环数据结构。事情是我需要停止函数执行，直到它到达它从其开始的元素。

我怎样才能做到这一点？

ish

该checked数组保留已调用id的所有对象（父对象）getNestedChildren的。

如果当前子项id位于该数组中，则不要将其作为子项包括在内。

var arr = [
  {"id": 1, "firstName": "Macko","parentId": 12},
  {"id": 2, "firstName": "Jess","parentId": 1},
  {"id": 3, "firstName": "Peter","parentId": 1},
  {"id": 4, "firstName": "Lisa", "parentId": 1},
  {"id": 5, "firstName": "Megan","parentId": 1},
  {"id": 6, "firstName": "John", "parentId": 4},
  {"id": 7, "firstName": "Joe", "parentId": 4},
  {"id": 8, "firstName": "Matthew","parentId": 2},
  {"id": 9, "firstName": "Peter","parentId": 2},
  {"id": 10, "firstName": "Dio","parentId": 5},
  {"id": 11, "firstName": "Hello","parentId": 5},
  {"id": 12, "firstName": "Ana", "parentId": 4}
];

var getNestedChildren = function(arr, id, checked) {

  var out = [];
  for (var i = 0; i < arr.length; i++) {
    if (arr[i].parentId === id && checked.indexOf(arr[i].id) === -1) {
      checked.push(id);
      var children = getNestedChildren(arr, arr[i].id, checked);
      if (children.length) {
        arr[i].children = children;
      }
      out.push(arr[i]);
    }
  }
  return out;

};

console.log(getNestedChildren(arr, 12, []));

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