Solution of weekly problem from Cassidy Williams's Newsletter

dayOffset.js

// Interview question of the week by Cassidy Williams's Newsletter
// This week's question courtesy of Louis:
// Write a function that takes the name of a day (e.g "Monday", "Tuesday") 
// and an integer offset, and returns the name of the day which would be the original + offset.

// Extra credit: do it in 1 line!

// Example:
// > dayOffset("Wednesday", 4)
// > "Sunday" 

dayOffset(day, offset) {
  const week = ['sunday', 'monday', 'tuesday', 'wednesday', 'thursday', 'friday', 'sunday'];
  return week[(week.findIndex(weekday => weekday === day.toLowerCase()) + offset) % 7];
}

console.log(dayOffset("Wednesday", 4));