如何获得Json的价值？

Question

我想从JSON数据中获取键和值，如下所示。{  "data": {    "listCard": {      "cards": [        {          "id": "2",          "title": "벗꽃볼사람",          "content": "하이",          "createdAt": "2019-04-17T16:06:31.962772+00:00",          "creator": {            "id": "2",            "name": "운영자"          }        },        {          "id": "1",          "title": "벗꽃볼사람",          "content": "하이",          "createdAt": "2019-04-17T16:06:14.789277+00:00",          "creator": {            "id": "2",            "name": "운영자"          }        }      ]    }  }}我使用下面显示的console.log（data.listCard）{cards: Array(2), __typename: "ListCardResponse"}cards: Array(2)0: {id: "2", createdAt: "2019-04-17T16:06:31.962772+00:00", updatedAt: "2019-04-17T16:06:31.962820+00:00", title: "벗꽃볼사람", content: "하이", …}1: {id: "1", createdAt: "2019-04-17T16:06:14.789277+00:00", updatedAt: "2019-04-17T16:06:14.789315+00:00", title: "벗꽃볼사람", content: "하이", …}length: 2__proto__: Array(0)__typename: "ListCardResponse"__proto__: Object但是我使用console.log（data.listCard.cards）它显示卡没有定义。最后我想使用data.listCard.cards.map。你可以帮帮我吗？