objectToQueryString (with lodash): pass in object containing key/value pairs which are converted to URL parameters

objectToQueryString.js

const _ = require('lodash'); 

// any parameters passed with a null value will not be added to the result
const objectToQueryString = obj => {
  const results = [];
  _.forOwn(obj, (value, key) => {
    if (Array.isArray(value)) {
      _.forOwn(value, value => {
        if (!_.isNil(value))
          results.push(`${key}=${value}`);
      });
    } else {
      if (!_.isNil(value))
        results.push(`${key}=${value}`);
    }
  });
  return results.join('&');
};

const obj = {
  a: 1,
  b: 'string',
  c: null,
  d: [
    'array',
    'of',
    'strings'
  ]
};

// expected output: a=1&b=string&d=array&d=of&d=strings
console.log(objectToQueryString(obj));