training.js

const list = {
  value: 1,
  next: {
    value: 2,
    next: {
      value:3
    }
  }
}


//while loop
const printList = (listArg) => {
  let list = listArg
  while (list) {
    console.log(list.value)
    list = list.next
  }
}
//recursion
const printListRec = (list) => {
  console.log(list.value)
  list.next && printListRec(list.next)
}
//revert recursin
const printListRecReverse = (list) => {
  list.next && printListRec(list.next)
  console.log(list.value)
}



// printListRec(list)
// printList(list)
//printListRecReverse(list)


const jwt = require('jsonwebtoken')

const token = jwt.sign({username: 'test', password: 'test'}, 'secret')
console.log(token)
const userData = jwt.decode(token)
console.log(userData)

// const promiseResolver = (arg, done) => {
//   let a
//   Promise.resolve(arg).then(ar =>{ 
//     a = ar
//     console.log(a)})
  
//   while(!a){
//    console.log('wait')
//    setTimeout(() => {
//     done()
//    }, 1123)
//   }
//   if(a){
//     console.log('in return')
//     return a
//   }
// }
// const x = promiseResolver(1, () => {})
// console.log(x)

// 86400000 мс - один день