将 K、V 对分配给 NodeJS 中的 JSON 对象

Question

I have a NodeJS script that takes data from a source in the form of "key, value" pairs, and I would like to put that data into a JSON object.

I am using SNMP to get the k, v pairs, where the key is the OID. I would like to then map those values onto a JSON object without having to iteratively check each OID against a known value.

The k,v pairs are stored in objects as such, and I have no flexibility over this incoming data.

let pair = {
    key: "abc...",
    value: "xyz..."
}

I have defined the JSON object as an empty structure.

let jsonObject = {
    ipaddress: "",
    network: {
        uptime: "",
        throughput: "",
        devices: ""
    }
}

And I iterate through my keys ( pairs is the name of an array containing the k,v objects)

for (let i = 0; i < pairs.length; i++) {
    if (pairs[i].key == "1.2.3.4.5.6.7") jsonObject.ipaddress = pairs[i].value;
    if (pairs[i].key == "2.3.4.5.6.7.8") jsonObject.network.uptime = pairs[i].value;
    if (pairs[i].key == "3.4.5.6.7.8.9") jsonObject.network.devices = pairs[i].value;
}

I would like to know if there is any way to simplify this, as I have around 200 keys to process (the above code is simply an example), and it doesn't seem particularly well optimised for me to iterate over every possible key.

EDIT: The jsonObject is a lot more complex than shown here, with lots of layers and the names of the keys do not match up 1:1 with the json object property names as shown.

EDIT 2: This seems like an odd situation, I know. For example, I want to take the K,V input:

Key            Value
1.2.3.4.5.6    "10.0.0.1"
2.3.4.5.6.7    "3 Days 14 Hours 32 Minutes"
3.4.5.6.7.8    "1.1.1.1"

And convert it to a dissimilarly named JSON object

{
    uptime: "3 Days 14 Hours 32 Minutes",
    networking: {
        ip: "10.0.0.1",
        dns: "1.1.1.1"
    }
}

Potentially using some form of mapping, instead of using ~200 if statements

Answer 1

Use the Array.prototype.reduce function.

const { name, ...properties } = pairs.reduce(
  (obj, { key, value }) => Object.assign(obj, { [key]: value }),
  {}
)

const obj = { name, properties }

Reduce will reduce an array into a scalar, in this case an object with all k,v pairs as fields with values on an object, starting with {} as a default value the merging each k,v pair 1 at a time.

Object.assign will merge objects, overwriting objects on the left with the fields of keys of objects on the right.

And finally the syntax to dynamically add a key on an object literal is { [k]: v }

By the way this is a useful trick for reducing the complexity of algorithms where you need to look up values in an array in a loop. Simply create an index of one array then in the loop, lookup in the index instead.

Answer 2

You can use Array.prototype.forEach for iterating and assigning the object.

 const jsonObject = { name: '', properties: { email: '', address: '', town: '' } }; const pairs = [{key: 'name', value: 'thatsimplekid'}, {key: 'email', value: 'aaa@domain.com'}, {key: 'town', value: 'myTown'}, {key: 'address', value:'123 main st' }]; pairs.forEach( ({key, value}) => jsonObject.hasOwnProperty(key) ? jsonObject[key] = value : jsonObject.properties[key] = value); console.log(jsonObject);

Answer 3

   for (let i = 0; i < pairs.length; i++) {
      const key = pairs[i].key;
      const value = pairs[i].value;

      if (pairs[i].key == "name") {
        jsonObject[key] = value;
      } else {
        jsonObject.properties[key] = value;
      }
    }

After the 'name' all values goes to the properties object, so a simple if would do it