What's My Age Again? - FreeCodeCamp Daily Challenge

2025-11-27 1 min

Table of Contents

What’s My Age Again? – Solving the Daily Challenge with a Blink-182 Twist

“What’s My Age Again?”

“And that’s about the time that she walked away from me… Nobody likes you when you’re 23!”

Yes, today’s challenge is named after the most iconic Blink-182 song from Enema of the State (1999). It’s an exercise to calculate your age, inspired by a song about not wanting to grow up.

The Problem Statement

Given a string with a birth date in the format YYYY-MM-DD, return the exact age as of today (November 27, 2025). And yes, you have to consider whether you’ve already had your birthday in 2025.

My First Impulse (the classic mistake)

2025 - birthYear

Done. Time to play some bass.

…But no, because someone born on November 28th is still a year younger. I thought I knew my age… until we have to program how to figure it out.

The Solution

function getAge(birthday) {
  const [y, m, d] = birthday.split('-').map(Number)
  const today = new Date()
  const age = today.getFullYear() - y

  const hasHadBirthdayThisYear
    = (today.getMonth() + 1) > m
      || ((today.getMonth() + 1) === m && today.getDate() >= d)

  return hasHadBirthdayThisYear ? age : age - 1
}

Key Concepts

Array destructuring: We extract year, month, and day directly from the string.
Date object: We use new Date() to get the current date.
No Date object for the birth date: We only need the individual components.
Age calculation: We subtract years and adjust depending on whether the birthday has already occurred this year.

“No one should take themselves so seriously…” — Blink-182, What’s My Age Again?

Additional Resources

freecodecamp daily-challenge