Codecademy - How old?

/*
Write a function, howOld(), that has two number parameters, age and year, and returns how old someone who is currently that age was (or will be) during that year. Handle three different cases:

If the year is in the future, you should return a string in the following format:
'You will be [calculated age] in the year [year passed in]'

If the year is before they were born, you should return a string in the following format:
'The year [year passed in] was [calculated number of years] years before you were born'

If the year is in the past but not before the person was born, you should return a string in the following format:
'You were [calculated age] in the year [year passed in]'
*/

const currentYear = 2021;

let howOld = (year, age) => {
  if(year > currentYear){
    return `You will be ${age+(year-currentYear)} in the year ${year}`;
  } else if (year < (currentYear-age)){
    return `The year ${year} was ${(currentYear-age)-year} years before you were born`;
  } else if (year < currentYear){
    return `You were ${age-(currentYear-year)} in the year ${year}`;
  }
}


console.log(howOld(2030, 20));
console.log(howOld(1960, 20));
console.log(howOld(2018, 20));
/*
You will be 29 in the year 2030
The year 1960 was 41 years before you were born
You were 17 in the year 2018