javascript - 递归地向数组中的每个对象添加相同的元素

Question

我让这个对象包含对象数组(“页面”)

var obj = {
    "pages" : [
        {   
            "title": "title one",
            "sub" : [
                { "title" : "title one one"},
                { "title" : "title one two"}
            ]
        },
        { "title" : "title two" },
        { 
            "title" : "title three",
            "sub" : [
                { "title" : "title three one"},
                { "title" : "title three two"},
                { "title" : "title three three"}
            ]
        }
    ]
}

和这样的预期结果(将“slug”元素添加到“页面”中的每个对象)

{
    "pages" : [
        {
            "title" : "title one",
            "slug" : "title-one",
            "sub" : [ 
                {
                    "title" : "title one one",
                    "slug" : "title-one-one"
                },
                {
                    "title" : "title one two",
                    "slug" : "title-one-two"
                }
            ]
        },
        {
            "title" : "title two",
            "slug" : "title-two"
        },
        {
            "title" : "title three",
            "slug"  : "title-three",
            "sub" : [
                {
                    "title" : "title three one",
                    "slug" : "title-three-one"
                },
                {
                    "title" : "title three two",
                    "slug" : "title-three-two"
                },
                {
                    "title" : "title three three",
                    "slug" : "title-three-three"
                }
            ]
        }
    ]
}

我想我可以这样做

function add_slug(array_of_obj)
{
    for (var item in array_of_obj) {

        //i am not sure about this:
        item.slug = item.title.replace(/ /g, '-');

        if(typeof item.sub !== undefined) {
            add_slug(item.sub);
        }
    }
}

add_slug(obj.pages);

但是我得到了 undefined item.title 我一直在修改函数，但它还不起作用，所以我需要帮助。谢谢。

Answer 1

更改为使用 for 循环而不是 for-in - 对数组更安全。

试试这个:

function add_slug(array_of_obj)
{
    for(var pageIdx = 0; pageIdx < array_of_obj.length; ++pageIdx) {
        var curPage = array_of_obj[pageIdx];

        if(curPage.title) {
            curPage.slug = curPage.title.split(' ').join('-');
        }

        if(curPage.sub) {
            add_slug(curPage.sub);
        }
    }
}

结果:

{
  "pages": [
    {
      "title": "title one",
      "sub": [
        {
          "title": "title one one",
          "slug": "title-one-one"
        },
        {
          "title": "title one two",
          "slug": "title-one-two"
        }
      ],
      "slug": "title-one"
    },
    {
      "title": "title two",
      "slug": "title-two"
    },
    {
      "title": "title three",
      "sub": [
        {
          "title": "title three one",
          "slug": "title-three-one"
        },
        {
          "title": "title three two",
          "slug": "title-three-two"
        },
        {
          "title": "title three three",
          "slug": "title-three-three"
        }
      ],
      "slug": "title-three"
    }
  ]
}