Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript Array Iteration Methods Array Manipulation Practice filter()

Posted by Peter Huang
Peter Huang
5,427 Points

Need help with this challenge

Need answer for this please and thank you

app.js 
const years = [1989, 2015, 2000, 1999, 2013, 1973, 2012];
let century20;

// century20 should be: [1989, 2000, 1999, 1973]
// Write your code below

years.filter(year => year.charAt(0) === "20");

1 Answer

Steven Parker
Steven Parker
230,274 Points
Steven Parker
Steven Parker
230,274 Points

Heres a few hints:

  • the years array contains numbers, and numbers don't have a charAt method
  • the character at position 0 of any string can never equal "20" because that's two characters
  • just testing the first character (or first digit) isn't enough to determine a 20th century year
  • remember that "20th century" includes years from 1901 to 2000