How to Use Lodash to Remove Keys from a Json Object

How to use lodash to remove keys from a JSON object?

You don't really need lodash for this. You can look at each key in your data and the just pull the values from each element of the array and concat it into a new array.

const data = {"north": [{"2018-07-01": {"date": "2018-07-01","name": "david","age": 11},"2018-07-02": {"date": "2018-07-02","name": "damo","age": 16},"2018-07-03": {"date": "2018-07-03","name": "dani","age": 12}}],"south": [{"2018-07-01": [{"fruit": "banana","date": "2018-07-01","name": "miller","age": 11},{"fruit": "mango","date": "2018-07-01","name": "mano","age": 11},{"fruit": "avocado","date": "2018-07-01","name": "karl","age": 14}],"2018-07-02": [{"fruit": "pineaplle","date": "2018-07-02","name": "gautier","age": 12},{"fruit": "apple","date": "2018-07-02","name": "gauteng","age": 9},{"fruit": "watermelon","date": "2018-07-02","name": "garzier","age": 12}]}]};
Object.keys(data).forEach(k => {    data[k] = data[k].reduce((a, c) => a.concat(...Object.values(c)), [])})console.log(data)

Removing object properties with Lodash

Get a list of properties from model using _.keys(), and use _.pick() to extract the properties from credentials to a new object:

var model = {
   fname:null,
   lname:null
};

var credentials = {
    fname:"xyz",
    lname:"abc",
    age:23
};

var result = _.pick(credentials, _.keys(model));

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.4/lodash.min.js"></script>

Lodash remove items recursively

_.transform() the object to another object, and while passing the values to the new object, check if the value is an object and if it has the 'reach' property, and if so use _.omit() to get a new object without reach:

var obj = {  total: 350,  SN1: {    reach: 200,    engagementRate: 1.35  },  SN2: {    reach: 150,    engagementRate: 1.19  }};
var result = _.transform(obj, function(result, value, key) {  result[key] = _.isObject(value) && `reach` in value ? _.omit(value, 'reach') : value;});
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.15.0/lodash.min.js"></script>

remove JSON key value, if the value inside the object exists before

Update: OP doesn't care about keys, so to just remove duplicate
values, and then of course the associated key, below is an example
using Set's.

Updated working snippet below ->

const data = {"modelhelloamazingIssue":{"modelhelloamazingIssueSevere":{"nameText":"Name","helloAnalysisType":["Normal","Mild","Moderate","Severe"],"helloText":"hello","abouthellosolo":"hello solo is a serious hello disorder that causes you to stop amazing during hello. It's important to understand the signs and symptoms.","noteText":"This is not a medical diagnosis and you may want to talk to your doctor.","buttonText0":"Next steps"},"modelhelloamazingIssueMild":{"nameText":"Name Example","helloAnalysisType":["Normal","Mild","Moderate","Severe"],"helloText":"hello","abouthellosolo":"My god this is so cool.","noteText":"This is not a medical diagnosis and you may want to talk to your doctor.","buttonText1":"Next steps"}}};

function removeDuplicateValues(obj) {
  const dups = new Set();
  function inner(o) {
    const needSplice = [];
    for (const [k, v] of Object.entries(o)) {     
      if (typeof v === 'object') {
        inner(v);
        if (!Object.keys(v).length) delete(o[k]);
      } else {
        if (dups.has(v)) {
          if (Array.isArray(o)) needSplice.unshift(k);
          else delete o[k];
        }
        else dups.add(v);
      }
    }
    for (const i of needSplice) o.splice(i, 1);
  }
  inner(obj);
}


removeDuplicateValues(data);

console.log(data);

lodash remove object from

You can use _.remove inside an forEach using an object as the predicate:

_.forEach(obj.products, function(product) {
  _.remove(product.comments, {id_comment: 1});
});

If an object is provided for predicate the created _.matches style callback returns true for elements that have the properties of the given object, else false.

var obj = {  id_order: '123123asdasd',  products: [{    description: 'Product 1 description',    comments: [{      id_comment: 1,      text: 'comment1'    }, {      id_comment: 2,      text: 'comment2'    }]  }, {    description: 'Product 2 description',    comments: [{      id_comment: 2,      text: 'comment2'    }, {      id_comment: 3,      text: 'comment3'    }]  }, {    description: 'Product 3 description',    comments: [{      id_comment: 1,      text: 'comment1'    }, {      id_comment: 2,      text: 'comment2'    }]  }]};
_.forEach(obj.products, function(product) {  _.remove(product.comments, {id_comment: 1});});
document.getElementById('result').innerHTML = JSON.stringify(obj, null, 2);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/3.10.1/lodash.min.js"></script><pre id="result"></pre>

How to remove empty object from JSON recursively using lodash

You can _.transform() the object recursively to a new one, and clean empty objects and arrays on the way.

Note: I've added more elements to the structure for demonstration

var template = {    personal: {},    education: {},    certificate: [{}, {"test": "Test"}, {}, {}, [{}], [{}, 1, []]],    experience: [[1, 2, [], { 3: [] }]]};
function clean(el) {  function internalClean(el) {    return _.transform(el, function(result, value, key) {      var isCollection = _.isObject(value);      var cleaned = isCollection ? internalClean(value) : value;
      if (isCollection && _.isEmpty(cleaned)) {        return;      }
      _.isArray(result) ? result.push(cleaned) : (result[key] = cleaned);    });  }
  return _.isObject(el) ? internalClean(el) : el;}
console.log(clean(template));

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Removing key in a JSON object but want to keep the original

You can use map and spread operator like below

let a = [          { firstName: 'Tony', lastName: 'Stack' },          { firstName: 'Iron', lastName: 'Man' }        ];        let removed = a.map(({firstName, ...lastName}) => lastName);
console.log('before:',a)console.log('after:', removed)

How to Use Lodash to Remove Keys from a Json Object