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 Basics Working with Strings Combine and Manipulate Strings

Raymond Parcels
Raymond Parcels
256 Points

Cannot read property '1' of null

I keep coming up with a "cannot read property '1' of null" error but I'm not sure what it means.

app.js
let firstName = 'Raymond';
let lastName = 'Parcels';
let role = 'developer';
let msg = firstName + ' ' + lastName + ':' + " ' ' + role + '.';
Johnathan Guzman
Johnathan Guzman
7,432 Points

Hey Raymond,

I think the issue at hand is that there are different data types being assigned to msg.

But here is my version of this code challenge:

let firstName= "Lee";
let lastName= "Louw";
let role= 'developer';

let msg = `${firstName} ${lastName}: ${role}`

1 Answer

Steven Parker
Steven Parker
231,269 Points

A very strange message indeed! But the issue is some extra symbols and unneeded punctuation in your concatenation sequence:

let msg = firstName + ' ' + lastName + ':' + " ' ' + role + '.';  // as originally posted
let msg = firstName + ' ' + lastName + ': ' + role;               // fixed