// note : every scope can access inner scope and outer scope
function outer() {
  let outer_value = “outer scope”
  function inner() {
  let inner_value = “inner scope”
  console.log(outer_value, inner_value)
  }
  inner();
}
outer()
// we can only call inner function in outer function scope
//but that not powerful , so if we want to use inner we should return it
function outerfun() {
  let outer_value = “outer scope”
  return function inner() {
  let inner_value = “inner scope”
  console.log(outer_value, inner_value)
  }
}
let innerfun=outerfun()
innerfun()

// that‘s called Closure
// The ability to access inner function by return it as value
// function return function
// to use inner function you should execute it
function setLocal(n) {
  let local = n;
  return () => console.log(local);
}
let local1 = setLocal(6);
local1() //6
let local2 = setLocal(9);
local2() //9

//In the example, multiplier is called , creates an scope and stored the value of factor
// and return The function
//when twice is called it multiplies its argument by 2 (factor).
function multiplier(factor) {
 return number => number * factor;
}
let twice = multiplier(2);
console.log(twice(5)) // 10
1