Removing Object Properties With Lodash

I have to remove unwanted object properties that do not match my model. How can I achieve it with Lodash? My model is: var model = { fname: null, lname: null } My controller

Solution 1:

You can approach it from either an "allow list" or a "block list" way:

// Block list// Remove the values you don't wantvar result = _.omit(credentials, ['age']);

// Allow list// Only allow certain valuesvar result = _.pick(credentials, ['fname', 'lname']);

If it's reusable business logic, you can partial it out as well:

// Partial out a "block list" versionvar clean = _.partial(_.omit, _, ['age']);

// and latervar result = clean(credentials);

Note that Lodash 5 will drop support for omit

A similar approach can be achieved without Lodash:

consttransform = (obj, predicate) => {
    returnObject.keys(obj).reduce((memo, key) => {
    if(predicate(obj[key], key)) {
        memo[key] = obj[key]
    }
    return memo
    }, {})
}

constomit = (obj, items) => transform(obj, (value, key) => !items.includes(key))

constpick = (obj, items) => transform(obj, (value, key) => items.includes(key))

// Partials// Lazy cleanconstcleanL = (obj) => omit(obj, ['age'])

// Guarded cleanconstcleanG = (obj) => pick(obj, ['fname', 'lname'])


// "App"const credentials = {
    fname:"xyz",
    lname:"abc",
    age:23
}

const omitted = omit(credentials, ['age'])
const picked = pick(credentials, ['age'])
const cleanedL = cleanL(credentials)
const cleanedG = cleanG(credentials)

Solution 2:

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);

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

If you don't want to use Lodash, you can use Object.keys(), and Array.prototype.reduce():

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

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

var result = Object.keys(model).reduce(function(obj, key) {
  obj[key] = credentials[key];
  return obj;
}, {});

console.log(result);

Solution 3:

You can easily do this using _.pick:

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

var credentials = {
  fname: 'abc',
  lname: 'xyz',
  age: 2
};

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


console.log('result =', result);

<scriptsrc="https://cdn.jsdelivr.net/lodash/4.16.4/lodash.min.js"></script>

But you can simply use pure JavaScript (specially if you use ECMAScript 6), like this:

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

const credentials = {
  fname: 'abc',
  lname: 'xyz',
  age: 2
};

const newModel = {};

Object.keys(model).forEach(key => newModel[key] = credentials[key]);

console.log('newModel =', newModel);

Solution 4:

Lodash unset is suitable for removing a few unwanted keys.

const myObj = {
    keyOne: "hello",
    keyTwo: "world"
}

unset(myObj, "keyTwo");

console.log(myObj); /// myObj = { keyOne: "hello" }

Solution 5:

Here I have used omit() for the respective 'key' which you want to remove... by using the Lodash library:

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

let result = _.map(credentials, object => {
                       return _.omit(object, ['fname', 'lname'])
                   })

console.log('result', result)