Simple way of having a clean code in JS using object literals

states.js

var capitalByState = {
  'MG': 'Belo Horizonte',
  'PR': 'Curitiba',
  'SP': 'São Paulo'
} // Allocated only one time and the data isn't INSIDE the function
  // so 'capitalByState' can come from a external source!

var States = {};
States.getCapitalCity = state => capitalByState[state] || 'Not Found'; // Again, allocated only one time, simulates static

States.getCapitalCity('PR') // Curitiba
States.getCapitalCity('??') // Not Found