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
Samuel Kleos
Front End Web Development Techdegree Student 13,307 PointsWhy doesn't parseInt(number).toString() work?
Here is my initial solution:
numberOf503 = phoneNumbers.reduce((acc, phone) => (parseInt(phone).toString().substring(0, 3) === "503")? acc+1 : acc, 0);
Here is the solution that worked
numberOf503 = phoneNumbers.reduce((acc, phone) => (phone.substring(1, 4) === "503") ? acc+1 : acc, 0);
const phoneNumbers = ["(503) 123-4567", "(646) 123-4567", "(503) 987-6543", "(503) 234-5678", "(212) 123-4567", "(416) 123-4567"];
let numberOf503;
// numberOf503 should be: 3
// Write your code below
1 Answer
Steven Parker
231,248 PointsSince all the phoneNumbers begin with a parenthesis, which is not a digit, then parseInt returns NaN.
That of course does not match "503".
Samuel Kleos
Front End Web Development Techdegree Student 13,307 PointsVery good to be aware of. Thank you. I will read docs for Built-in objects more carefully next time.
Rich Donnellan
Treehouse Moderator 27,696 PointsRich Donnellan
Treehouse Moderator 27,696 PointsI updated the question with code formatting hinting and fixed a typo in the title.