javascript - jQuery 递归地遍历对象数组并返回一个值

Question

我有以下 json，它表示网站上的页面，这些页面通过项目数组具有子页面，当前包含 2 个顶级项目 - 关于和服务:

var data = '[{"id":107,"name":"About Us","route":"page","slug":"about","parent":0,"module":1,"items":[{"id":118,"name":"About Sub Page","route":"page","slug":"about-sub-page","parent":107,"items":[]}]},{"id":129,"name":"Services","route":"page","slug":"services","parent":0,"module":1,"items":[{"id":174,"name":"Services sub page","route":"page","slug":"services-sub-page","parent":129,"items":[]}]}]';

我正在尝试编写一个函数，该函数在对象数组(data = JSON.parse(data))上递归迭代并识别顶级项目的索引。例如，在我的函数中，如果我使用 'about' slug，它将返回 0，'about-sub-page' 也会返回 0。同样，“services-sub-page”将返回 1。

我现在有这个:

data = JSON.parse(data);

function check(slug,data) {
 var result;
 $.each(data, function(index){
  if (this.slug === slug) {
    result = index;
    return false;
  }
  else {
   check(slug,this.items);
  }
 });
   return result;
 }

如果我通过顶级 slug 例如，这可以正常工作

 var index = check('about',data);
 console.log(index); // returns 0

 var index = check('services',data);
 console.log(index); // returns 1

但是，如果我尝试使用子页面，我会得到未定义

 var index = check('services-sub-page',data);
 console.log(index); // returns undefined

我相信我需要返回 false 才能跳出每个循环，但不确定为什么当我尝试递归使用该函数时它不起作用。

Answer 1

您可以使用Array#some() ，因为如果满足条件，就会停止迭代。

var data = '[{"id":107,"name":"About Us","route":"page","slug":"about","parent":0,"module":1,"items":[{"id":118,"name":"About Sub Page","route":"page","slug":"about-sub-page","parent":107,"items":[]}]},{"id":129,"name":"Services","route":"page","slug":"services","parent":0,"module":1,"items":[{"id":174,"name":"Services sub page","route":"page","slug":"services-sub-page","parent":129,"items":[]}]}]';

function check(slug, data) {
    function iter(a, i) {
        if (a.slug === slug || Array.isArray(a.items) && a.items.some(iter)) {
            index = i;
            return true;
        }
    }

    var index,
        array = JSON.parse(data);

    array.some(iter)
    return index;
}

document.write(check('about', data) + '<br>');
document.write(check('services', data) + '<br>');
document.write(check('services-sub-page', data) + '<br>');