How to filter a dictionary by value in JavaScript?

Question

I am writing a script to create a dictionary called dict, where I store the the frequencies of some words that I have in a text area. My array looks like this:

var dict = removeArray.reduce(function(p,c) {     if (p[c] === undefined) {         p[c] = 1;     } else {         p[c]++;     }     return p; }, {}); 

I would like to filter the elements of this dictionary by their value. I need to create a list with the words that have a value greater than one. My dictionary looks like this:

{     "92173": 6,     "C": 6,     "GJHGWO.NAYE": 1,     "GJHGX4.NAYE": 1,     "GJHGX6.NAYE": 1,     "GJHGX8.NAYE": 1,     "GJHGXA.NAYE": 1,     "GJHGXC.NAYE": 1,     "RBD": 10,     "RBD3": 2,     "SAMBORNSiPOSSSTHRa": 2,     "SAMBORNSiPOSSSTHRa1": 2,     "SAMBORNSiPOSSSTHRa2": 2,     "X": 4,     "X3": 2 } 

In order to achieve that I tried using lodash, as follows:

var filtered = _.find(dict, function(user) {     return user.frecuency > 1; }); 

But I failed since I got:

undefined 

I don't know how to use lodash appropriately to filter this array.

My complete code looks like this:

var splitWords = document.getElementById("texto").value.split(/[["\|~]/);  var removeArray  = _.remove(splitWords, function (word) {      return word !== '' && word !== ' ' && word !== '\n'  });    var dict = removeArray.reduce(function(p,c) {      if (p[c] === undefined) {          p[c] = 1;      } else {          p[c]++;      }      return p;  }, {});  console.log(dict);    var filtered = _.find(dict, function(user) {    return user.frecuency > 1;  });    console.log(filtered)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>  <p id="demo"></p>  <textarea cols="150" rows="15" id="texto">  "RBD|X|RBD3|C|92173~GJHGWO.NAYE"  "SAMBORNSiPOSSSTHRa1"  "RBD|X|RBD|C|92173~GJHGX4.NAYE"  "SAMBORNSiPOSSSTHRa"  "RBD|X3|RBD3|C|92173~GJHGX6.NAYE"  "SAMBORNSiPOSSSTHRa1"  "RBD|X|RBD|C|92173~GJHGX8.NAYE"  "SAMBORNSiPOSSSTHRa2"  "RBD|X|RBD|C|92173~GJHGXA.NAYE"  "SAMBORNSiPOSSSTHRa2"  "RBD|X3|RBD|C|92173~GJHGXC.NAYE"  "SAMBORNSiPOSSSTHRa"  </textarea>

Answer 1

You could use reduce again to achieve that in plain JavaScript:

var filtered = Object.keys(dict).reduce(function (filtered, key) {     if (dict[key] > 1) filtered[key] = dict[key];     return filtered; }, {}); 

With some ES6 features, such as arrow functions, spread syntax, Object.entries, ... it can look like this:

var filtered = Object.assign({}, ...     Object.entries(dict).filter(([k,v]) => v>1).map(([k,v]) => ({[k]:v})) ); 

Or using the newer Object.fromEntries:

var filtered = Object.fromEntries(Object.entries(dict).filter(([k,v]) => v>1)); 

Using Lodash

There were a few issues with your attempt with lodash:

• _.find is not intended for returning an object that takes a selection of key/values from a given object. You would need _.pickBy for that.
• Your object values do not have a frecuency property; they are primitive values, so you should just have to return user > 1

Lodash code:

var filtered = _.pickBy(dict, function(user) {   return user > 1; });