javascript - 以动态深度访问嵌套数组

Question

我有以下一段 json，它遵循特定的模式，但每个对象可以有任意数量的 children 并且每个 children > 对象可以有任意数量的子对象 ..

[
  {
    "name": "1st level",
    "parentId": "",
    "id": "dummyvalue1",
    "children": [
      {
        "name": "2nd level child",
        "parentId": "dummyvalue1",
        "id": "dummyvalue2"
      },
      {
        "name": "another 2nd level child",
        "id": "dummyvalue3",
        "children": [
          {
            "name": "3rd level child",
            "id": "dummyvalue4",
            "children": [
              {
                "name": "4th level child",
                "parentId": "dummyvalue4",
                "id": "dummyvalue5"
              }
            ],
            "parentId": "dummyvalue3"
          }
        ],
        "parentId": "dummyvalue1"
      }
    ]
  }
]

问题是，我只需要访问此嵌套对象/数组结构中特定深度的对象。

并且该深度是动态的。

如果深度等于3，那么我想在该级别的children数组中添加一个新的虚拟对象。所以新的结构看起来像这样..

[
  {
    "name": "1st level",
    "parentId": "",
    "id": "dummyvalue1",
    "children": [
      {
        "name": "2nd level child",
        "parentId": "dummyvalue1",
        "id": "dummyvalue2"
      },
      {
        "name": "another 2nd level child",
        "id": "dummyvalue3",
        "children": [
          {
            "name": "3rd level child",
            "id": "dummyvalue4",
            "children": [
              {
                "name": "4th level child",
                "parentId": "dummyvalue4",
                "id": "dummyvalue5"
              }
            ],
            "parentId": "dummyvalue3"
          },
          {
            "name": "NEW OBJECT",
            "parentId": "dummyvalue3",
            "id": "random"
          }
        ],
        "parentId": "dummyvalue1"
      }
    ]
  }
]

有没有一种干净的方法可以做到这一点？而不是试图迭代到正确的级别的巨大循环。另外，我也不认为我可以使用点表示法，因为级别数和 深度 变量是动态的

Answer 1

我创建了这个函数:

function addChild(currentChild, childToAdd, depth) {
  if (depth === 1) {
    currentChild.children.push(childToAdd);
    return;
  }

  const nextChild = currentChild.children.filter(child => child.children && child.children.length)[0];

  if (!nextChild) {
     if (currentChild.children && currentChild.children.length) {
       currentChild.children[0].children = [childToAdd];
     } else {
       currentChild.children = [childToAdd];
     }
     return;
  }

  addChild(nextChild, childToAdd, depth - 1);
}

它需要 3 个参数:

1. 当前 child
2. 要添加的子项
3. 剩余深度

如果深度为1，它只是将子添加到子。如果没有，它会查找 children 内部，使用第一个 children 并递归调用同一函数。

const data = [
  {
    "name": "1st level",
    "parentId": "",
    "id": "dummyvalue1",
    "children": [
      {
        "name": "2nd level child",
        "parentId": "dummyvalue1",
        "id": "dummyvalue2"
      },
      {
        "name": "another 2nd level child",
        "id": "dummyvalue3",
        "children": [
          {
            "name": "3rd level child",
            "id": "dummyvalue4",
            "children": [
              {
                "name": "4th level child",
                "parentId": "dummyvalue4",
                "id": "dummyvalue5"
              }
            ],
            "parentId": "dummyvalue3"
          }
        ],
        "parentId": "dummyvalue1"
      }
    ]
  }
]

function addChild(currentChild, childToAdd, depth) {
  if (depth === 1) {
    currentChild.children.push(childToAdd);
    return;
  }
  
  const nextChild = currentChild.children.filter(child => child.children && child.children.length)[0];
  
  if (!nextChild) {
     if (currentChild.children && currentChild.children.length) {
       currentChild.children[0].children = [childToAdd];
     } else {
       currentChild.children = [childToAdd];
     }
     return;
  }

  addChild(nextChild, childToAdd, depth - 1);
}

addChild(data[0], {foo: 'bar'}, 3);
addChild(data[0], {bar: 'baz'}, 2);
addChild(data[0], {baz: 'foo'}, 1);
addChild(data[0], {extraChild: 'foo'}, 4);


console.log(data);