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()

Jiten Mehta
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Jiten Mehta
Front End Web Development Techdegree Graduate 21,209 Points
Posted by Jiten Mehta
.a{fill-rule:evenodd;}techdegree seal-36
Jiten Mehta
Front End Web Development Techdegree Graduate 21,209 Points

Is there a way to refactor this code?

Hey guys, currently working on a code challenge for the filter method.

Ive completed it but i feel i could use less code to achieve this.

I am aware of one line arrow functions, however, the syntax always confuses me.

Any recommendations will be appreciated:).

Thanks, Jiten.

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

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

const twoThoandAbove = year => { 
  if (year <= 2000) {
    return year;
  }
 }

century20 = years.filter(twoThoandAbove);

1 Answer

Steven Parker
Steven Parker
231,184 Points
Steven Parker
Steven Parker
231,184 Points

The function doesn't need to return the year, just a Boolean to indicate if the filter should use the value. And you can define it as an anonymous function expression directly in the call to "filter". Combining that with the compact syntax allows the task to be done with this small one-liner:

century20 = years.filter( year => year <= 2000 );