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

Nathan Fite
Nathan Fite
416 Points
Posted by Nathan Fite
Nathan Fite
416 Points

role.toUpperCase(); what gives?

Can someone spot the error when I try to capitalize "DEVELOPER" at the end of my msg? I keep getting a null error.

app.js 
let firstName = "Nathan";
let lastName = "Fite";
let role = 'developer';
let msg = firstName + ' ' + lastName + ': ' + role;
let msg = firstName + ' ' + lastName + ': ' + role.toUpperCase();

1 Answer

Tomas Schaffer
Tomas Schaffer
11,606 Points
Tomas Schaffer
Tomas Schaffer
11,606 Points

you are dclaring second time the same variable in same scope. You may rewrite the let msg like this:

msg = firstName + ' ' + lastName + ': ' + role.toUpperCase();

variable already exists so you cant create the same variable twice.

or you can combine string like this alsowith template literals:

msg = firstName lastName: ${role.toUpperCase()}