MahmoudAgamy

if ENV['REDIS_ACCESS_MODE'] == 'readonly'
  class Redis
    class Client
      WRITE_COMMANDS = ::Rails.cache.data.command.map { |a| a[0] if a[2].include?('write') }.compact.to_set.freeze

      def process(commands)
        if commands.flatten.any? { |c| WRITE_COMMANDS.include?(c.to_s) }
          raise NotImplementedError, "REDIS_ACCESS_MODE is set to 'readonly', disallowing writes"
        end

MahmoudAgamy

# config/initializers/redis.rb
require 'redis'

# Disables the `flushdb` and `flushall` commands.
class Redis
  module DangerousCommands
    def flushdb
      raise 'This is EXTREMELY DANGEROUS! If you really want to EMPTY THE ENTIRE DATABASE, do it from `redis-cli`.'
      # You could call `super` here if you want to allow access in some circumstances.
    end

MahmoudAgamy

let obj =  { a: 2, b: 4, c: 2, k: 1 }

let sortedKeys = Object.keys(obj).sort((a,b)=>{obj[b]-obj[a]})
                                                          
console.log(sortedKeys) // [ 'b', 'a', 'c', 'k' ]

MahmoudAgamy

let sortedObj = sortedKeys.reduce((acc,ltr) => {
    acc[ltr] = obj[ltr]
    return acc
  },{})

console.log(sortedObj) // { b: 4, a: 2, c: 2, k: 1 }

MahmoudAgamy

let obj =  { a: 2, b: 4, c: 2, k: 1 }

let sortedKeys = Object.keys(obj).sort((a,b)=>obj[b]-obj[a])

console.log(sortedKeys) // [ 'b', 'a', 'c', 'k' ]

MahmoudAgamy

// subtracting arr2 from arr1
let subtracting = arr1.filter(x => !arr2.includes(x));

// intersection between arr1 and arr2
let intersection = arr1.filter(x => arr2.includes(x));

// NotIntersection: all elements but intersection elements
let NotIntersection = 
                   arr1.filter(x => !arr2.includes(x))
                   .concat(arr2.filter(x => !arr1.includes(x)));

MahmoudAgamy

let strArr = [ 'a', 'a', 'b', 'b', 'b', 'c', 'b', 'c', 'k' ]

let uniqueVal = strArr.filter((elem, i) => strArr.indexOf(elem) == i);

console.log(uniqueVal) // [ 'a', 'b', 'c', 'k' ]

MahmoudAgamy

let obj =  { a: 2, b: 4, c: 2, k: 1 }

let sortedArr = Object.entries(obj).sort((a,b)=> b[1] - a[1])
console.log(sortedArr) // [ [ 'b', 4 ], [ 'a', 2 ], [ 'c', 2 ], [ 'k', 1 ] ]

let sortedToObject = sortedArr.reduce((acc, itr)=>{
  acc[itr[0]] = itr[1]
  return acc;
}, {})
console.log(sortedToObject) // { b: 4, a: 2, c: 2, k: 1 }

MahmoudAgamy

let string = "aabbbcbck"
let strArr = string.split("") // [ 'a', 'a', 'b', 'b', 'b', 'c', 'b', 'c', 'k' ]

// Array to object using For-Loop - counting each letter occurances
let usingForLoop = (arr)=>{
  let newObj={};
  for(let i=0; i<arr.length; ++i){
      newObj[arr[i]] = newObj[arr[i]]+1 || 1;
    }
  return newObj;

MahmoudAgamy

let string = "aabbbcbck"
let strArr = string.split("") // [ 'a', 'a', 'b', 'b', 'b', 'c', 'b', 'c', 'k' ]

// Array to object using reduce - counting each letter occurances
let obj = strArr.reduce((acc,ltr) => {
    acc[ltr] = ++acc[ltr] || 1
    return acc
  },{})
console.log("reduce - object: ", obj) // { a: 2, b: 4, c: 2, k: 1 }