Understanding Case Sensitivity in Variables: undefined?

Tell us what’s happening:
I got the error var studlyCapVar is not defined until I changed my code from
var studlyCapVar;
studlyCapVar = 10;
var studlyCapVar;
var studlyCapVar = 10;
is this right? I have to use var everytime i assign a value to a variable I allready declared?

Your code so far

// Declarations
var C;
var properCamelCase;
var TitleCaseOver;

// Assignments
PRoperCAmelCAse = "A String";
tITLEcASEoVER = 9000;

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36.

Link to the challenge:

in this challenge you just need to change the variable names so that they use camel case and they match in both places
moving things around is not what you are asked to do
if you have issues figuring out what’s the proper camel case form of the variables, check the tests - those not passing means that one or both of the variable names don’t match the expected name

I have no problem with camelcases. It was just that I got the error that the variabel wasn’t defined, until I put var in the beginning of the assignment.
As you can see in the message I wrote, It is exactly the same word in declaration as in assignment, but still it didnt work. And It would be nice if you pointed out where in the message above I hadn’t done the camel case right.

in the part “Your code so far”
I see a line with var C and an other line with STUDLYCAPVAR = 10

if it was giving you that error you were missing something