在Javascript中解析Json-Google标记管理器

我有这样的剧本：

function() {
  var publishedDate = "";
  var yoastInfo = JSON.parse(document.head.querySelector('.yoast-schema-graph.yoast-schema-graph--main').innerHTML);
  vars = yoastInfo["@graph"];
  for(var i in vars) {
    if(vars[i]['@type'] === 'WebPage') {
      pubDateRaw=(vars[i]['datePublished']);
      break;
    }
  }
  publishedDate.concat(pubDateRaw.substring(0,4),pubDateRaw.substring(5,7),pubDateRaw.substring(8,10));
  return publishedDate;
}

当我运行代码时，它会给我一个

”

，而不是日期

以下是json：

{
  "@context": "https://schema.org",
  "@graph": [   

    {
      "@type": "WebPage",
      "@id": "id234234",
      "url": "https://www.whatevver.com",
      "inLanguage": "de-DE",
      "name": "this is the name",
      "isPartOf": {
        "@id": "id234234
      },
      "primaryImageOfPage": {
        "@id": "id234234"
      },
      "datePublished": "2020-01-14T07:46:12+00:00",
      "dateModified": "2020-01-15T08:04:50+00:00",
      "description": "description "
    },

  ]
}

所以我需要从json中提取datePubished。我的代码有什么问题

编辑

在你们的帮助下，我制作了以下脚本：

function() {
  var publishedDate = "";
  var yoastInfo = JSON.parse(document.head.querySelector('.yoast-schema-graph.yoast-schema-graph--main').innerHTML); 
  vars = yoastInfo["@graph"];
  for(var i in vars) {
    if(vars[i]['@type'] === 'WebPage') {
      publishedDate=(vars[i]['datePublished']); 
    }
  }



  return publishedDate;
}

现在我需要将日期时间

2020-01-14T07:46:12+00:00

缩短到

2020-01-14

最好的解决方案是什么

EDIT2

在以下位置找到解决方案：

给定JSON:

{
  "@context": "https://schema.org",
  "@graph": [   

    {
      "@type": "WebPage",
      "@id": "id234234",
      "url": "https://www.whatevver.com",
      "inLanguage": "de-DE",
      "name": "this is the name",
      "isPartOf": {
        "@id": "id234234" // MAKE IT AS A STRING
      },
      "primaryImageOfPage": {
        "@id": "id234234"
      },
      "datePublished": "2020-01-14T07:46:12+00:00",
      "dateModified": "2020-01-15T08:04:50+00:00",
      "description": "description "
    },

  ]
}

请按照代码中的注释进行澄清。谢谢：））

并查看链接以了解更多说明：

---

基本上，您只想从给定的JSON返回datePublised？您没有在for循环中尝试一些调试内容吗？似乎这个条件永远不会满足是的，基本上我想返回datePubished-并将其推送到数据层。好的，我知道了。您希望日期格式如何？如果更新了我的问题，结果应该是YYYY-MM-DDYeah，对Tagmanager（ES6）稍加修改即可。也许你能再帮我一次？现在我得到了完整的时间日期字符串，但我只需要YYYY-MM-dd函数formatDate（Date）{var d=new-Date（Date），month=''+（d.getMonth（）+1），day=''+d.getDate（），year=d.getFullYear（）；if（month.length<2）month='0'+month；if（day.length<2）day='0'+day；返回[year，month，day].join（“/”）；}formatDate（publishedDate）；您可以使用moment.js进行更多简化。

function() {
  let publishedDate = "";
  const yoastInfo = JSON.parse(document.head.querySelector('.yoast-schema- 
  graph.yoast-schema-graph--main').innerHTML); // I HOPE YOURE ABLE TO EXTRACT THE JSON HERE IN yoastInfo.
  vars = yoastInfo["@graph"];
  for(var i in vars) {
    if(vars[i]['@type'] === 'WebPage') {
      publishedDate=(vars[i]['datePublished']); // YOU ARE GETTING EMPTY STRING BECAUSE YOU'RE SETTING VARIABLE CALLED 'publishedDate' AND SETTING VALUE IN 'pubDateRaw'.
    }
  }
  return publishedDate;
}