Privates in JavaScript Classes, medium, using closures, es5

private-using-closure-es5.js

function Bank() {
  // public variables
  this.name = 'B7'
  
  // public methods
  this.getBalance = function() {
    return _balance
  }
  this.addToBalance = function(count) {
    _addBalance(count)
    return this.getBalance()
  }
  
  
  // private variables
  var _balance = 0
  var _logs = []
  
  // private methods
  function _addBalance(count) {
    _logBankChange('add', count)
    _balance += count
  }
  function _logBankChange(type, count) {
    _logs.push({ type, count })
  }
}