嵌套 JSON 数据的故障处理

Question

I have a JSON data and i'm having trouble with one nested object. You can see there is two metadata object, my aim is to get image link.

obj.metadata.url

is working, but this isn't work.

obj.metadata.metadata.image 

what am i missing here?

{
  "tokenId": "0",
  "metadata": {
    "url": "https://gateway.pinata.cloud/ipfs/QmSnTNGbhD/0",
    "metadata": {
      "name": "Illuminati #0",
      "image": "https://gateway.pinata.cloud/ipfs/QmW8pAhkNr/5499.png",
      "attributes": [
        {
          "trait_type": "Background",
          "value": "Stained Glass"
        },
        {
          "trait_type": "Frames",
          "value": "Stained Glass"
        }
      ]
    },
    "tokenId": "0"
  }
}

Answer 1

From your question it seems that you are dealing with JSON data instead of JavaScript objects. In order to get the attributes of JSON, you will first need to parse the JSON using JSON.parse() , then you can use . to get the properties you want.

data = {
  "tokenId": "0",
  "metadata": {
     "url": "https://gateway.pinata.cloud/ipfs/QmSnTNGbhD/0",
      "metadata": {
      "name": "Illuminati #0",
      "image": "https://gateway.pinata.cloud/ipfs/QmW8pAhkNr/5499.png",
      "attributes": [
      {
        "trait_type": "Background",
        "value": "Stained Glass"
      },
      {
        "trait_type": "Frames",
        "value": "Stained Glass"
      }
     ]
  },
  "tokenId": "0"
  }
};

obj = JSON.parse(data);
console.log(obj.metadata.url)
// 'https://gateway.pinata.cloud/ipfs/QmSnTNGbhD/0'
console.log(obj.metadata.metadata.image);
// 'https://gateway.pinata.cloud/ipfs/QmW8pAhkNr/5499.png'