var assert = require('assert')

function deepEqual(obj1, obj2){
  var keys1 = Object.keys(obj1)
  var keys2 = Object.keys(obj2)
  
  if(keys1.length !== keys2.length) return false
  
  for(var key in obj1){

    if(!obj2.hasOwnProperty(key))  return false
    
    else if(typeof obj1[key] !== 'object' && typeof obj2[key] !== 'object'){
      if(obj1[key] !== obj2[key]) return false
    }
    
    else if(typeof obj1[key] === 'object' && typeof obj2[key] === 'object'){
      
      if(getType(obj1[key]) !== getType(obj2[key])) return false
      
      switch(getType(obj1[key])){
          
        // case '[object Array]':
        //   if(obj1[key].length !== obj2[key].length) return false
        //   for(var i = 0; i < obj1[key].length; i++){
        //     if(obj1[key][i] !== obj2[key][i]) return false
        //   }
        //   break
          
        case '[object Object]':
          if(!deepEqual(obj1[key], obj2[key])) return false
          break
        
        // case '[object Function]':
        //   //???
        //   break
          
          //...many more
      }
      
      
    }
      
    else return false
    
  }
  
  return true
  
}

function getType(obj){
  return Object.prototype.toString.call(obj)
}


var a = {1: {2: 3}, 4: 5}
var b = {1: {2: 3}, 4: 5}
var c = {1: {2: {3: 4}}}
var d = {1: {2: {3: 4}}}
assert.equal(deepEqual(a, b), true)
assert.equal(deepEqual(a, c), false)
assert.equal(deepEqual(c, d), true)
console.log(a === b)
console.log(a == b)