javascript - 向嵌套对象树中的 Javascript 对象添加序号

Question

我有一个如下所示的对象，我正在寻找一种方法来为树中的每个子对象添加一个属性。也就是我想给对象加一个数，从0到n递增。我知道我可以使用递归函数遍历对象，但是由于变量范围，我无法在遍历树时使用简单的递增变量进行计数。

当前对象:

var tree = [
{
    name: 'a',
    children: []
},{
    name: 'b',
    children: [
        {
            name: 'c',
            children: []
        }
    ]
},
{
    name: 'd',
    children: [
        {
            name: 'e',
            children: [
                {
                    name: 'f',
                    children: []
                },
                {
                    name: 'g',
                    children: []
                }
            ]
        }
    ]
}
];

想要的对象:

var tree = [
{
    name: 'a',
    number: 0,
    children: []
},{
    name: 'b',
    number: 1,
    children: [
        {
            name: 'c',
            number: 2,
            children: []
        }
    ]
},
{
    name: 'd',
    number: 3,
    children: [
        {
            name: 'e',
            number: 4,
            children: [
                {
                    name: 'f',
                    number: 5,
                    children: []
                },
                {
                    name: 'g',
                    number: 6,
                    children: []
                }
            ]
        }
    ]
}
];

Answer 1

您只需要在递归 函数之外设置计数器变量并在循环对象之前递增它。

var tree = [{"name":"a","children":[]},{"name":"b","children":[{"name":"c","children":[]}]},{"name":"d","children":[{"name":"e","children":[{"name":"f","children":[]},{"name":"g","children":[]}]}]}];

function addNumber(input) {
  var counter = 0;

  function rec(data) {
    data.forEach(function(e) {
      if (typeof e == 'object' && !Array.isArray(e)) {
        e.number = counter++;
        for (var p in e) {
          if (typeof e[p] == 'object') rec(e[p])
        }
      } 
    })
  }
  rec(input)
}

addNumber(tree);
console.log(tree)