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

Jordan Branch
Jordan Branch
2,762 Points
Posted by Jordan Branch
Jordan Branch
2,762 Points

Cannot read property '1' of null

I do not fully understand what I'm doing wrong.

app.js 
let firstName = 'jordan';
let lastName = 'branch';
let role = 'developer';
let msg = firstName + " " + lastName + ": " + role;
let msg = firstName + " " + lastName + ": " + role.toUpperCase;

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

The hint isn't very helpful, but there are two issues here:

  • you should only declare a variable once (using "let")
  • when you call a function (like toUpperCase), you need parentheses after the name