反应提取嵌套的 json object

Question

How can I extract the 'jobs' object from a nested json list like this:

result:
{
 person:
  [
    {
       name: ""
       address: ""
       jobs: [
         {
           company:""
          },
          {
            company:""
           }
         ]
       }
      ]
     }

Thank you

Answer 1

Write a generic method to extract object properties.

function onExtract(key, data) {
  if (isObject(data)) {
    for (let item in data) {
      if (key === item) {
        return data[item];
      }
      const res = onExtract(key, data[item]);
      if (res !== null) return res;
    }
  }
  if (isArray(data)) {
    for (let item of data) {
      const res = onExtract(key, item);
      if (res !== null) return res;
    }
  }
  return null;
}

function isObject(obj) {
  return Object.prototype.toString.call(obj) === "[object Object]";
}
function isArray(arr) {
  return Object.prototype.toString.call(arr) === "[object Array]";
}


// test
const data = {
  person: [
    {
      name: "",
      address: "",
      jobs: [
        {
          company: ""
        },
        {
          company: ""
        }
      ]
    }
  ]
};

console.log(onExtract("jobs", data));

Answer 2

let's say you have a return var that contains this json value

let mappedCompanies = return.person.map(person => 
     person.jobs.map(job => job.company)
).flatMap(m => m)

mappedCompanies would contain an array with all the companies names for each one of the registers in "person", all as one array of strings

you can read more about Array.map() here: https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Global_Objects/Array/map

Answer 3

A dynamic way to query the person[] and find jobs, is to use the javascript map() method.

Here is the code without comments.

  const personsJobs = (personName, personAddress) => {
    const jobs = result.person.map((el) => {
        if (el.name === personName && el.address === personAddress) {
          return el.jobs;
        } else {
          return null;
        }
      })
      .filter((el) => el !== null);

    return jobs;
  };

  console.log(personsJobs("wyatt", "1234 test ln"));

Here is the code with comments to explain how the personsJob function works.

// Blow is an ES6 arrow function with the parameters 'personName' and 'personAddress',
// which represents the person in which you are querying for jobs (using both a persons 
// name and address so in the case of persons with the same name, you only find the jobs
// of the person you want).

  const personsJobs = (personName, personAddress) => {

// Since 'person' is an array, we can use the 'map' method as stated before, which 
// will create a new array (jobs) that will store the jobs a specific person has.

    const jobs = result.person.map((el) => {

// el stands for the current position in the person array. 
// if el's (the current person) name and address values are equal to that of the 
// parameters personName and personAddress, then that persons jobs are added to the jobs // array, however, if el does not satisfy the two parameters, null is added to the jobs
// array.
// The array, upon completion, will look something like this: ["programmer", null, null]

        if (el.name === personName && el.address === personAddress) {
          return el.jobs;
        } else {
          return null;
        }
      })

// Finally, the filter method is called to remove all null values so that you will
// only have the persons job in the jobs array.
// After filtering, the array will look like this: ["programmer"]

      .filter((el) => el !== null);

    return jobs;
  };

// Prints the array of wyatt's jobs

  console.log(personsJobs("wyatt", "1234 test ln"));

So, following the conclusion of the function, you will have dynamically found the jobs of a specific person.

Answer 4

you can use flatMap function like:

 const jobsData = result.person.flatMap(item => item.jobs);

Answer 5

Here is a flexible solution using object-scan

 // const objectScan = require('object-scan'); const data = { person: [{ name: '', address: '', jobs: [{ company: '' }, { company: '' }] }] }; console.log(objectScan(['person[*].jobs'], { reverse: false, rtn: 'value' })(data)); // => [ [ { company: '' }, { company: '' } ] ]

 .as-console-wrapper {max-height: 100%;important: top: 0}

 <script src="https://bundle.run/object-scan@14.0.0"></script>

Disclaimer : I'm the author of object-scan