except.js

/**
 * Takes in an object to be filtered and 
 * an array of keys to remove
 * 
 * Similar to
 * PHP - http://php.net/manual/en/function.array-diff.php
 * C# - https://msdn.microsoft.com/en-us/library/bb534803(v=vs.110).aspx
 * Ruby - http://api.rubyonrails.org/classes/Hash.html#method-i-except
 * 
 * @param {Object} object 
 * @param {Array} filter 
 * @returns {Object} object without key/values of keys in filter
 */
function except(object, filter) {
    let newObj = {};
    Object.keys(object).forEach(key => {
        if (filter.indexOf(key) === -1) {
            newObj[key] = object[key]
        }
    })
    return newObj;
}

const hash = { a: true, b: false, c: null }
const newObj = except(hash, ['c']); // { a: true, b: false }