I'm not sure there is a correct answer. The following code will report errors with variables "first", "name and "last"

I am not certain what you are saying, I did not personally look at the video yet but I would assume that if you had something like concatenating two strings then you would do something like this.

//Just an example
var first_name = "John";
var last_name = "Doe";
console.log(first_name + " " + last_name);

Now I am assuming that is what it is actually asking for, but again I have not looked at the video. I think I looked at it almost two years ago.

Let me know if there is anything else I can help you with, or if you wanna reword your question differently.

This is a very strange thing. When I copy and paste the text of quiz, everything is ok. But when I see it in my browser, underscore characters are not displayed in function call.

Here is the screenshot. link

I am not sure why that shows like that, but the thing is if you are concatenating strings if you do not declare a space on either of the variables values, then there will not be a space between the strings.

var first_name = "John"; var last_name = "Doe";

console.log(first_name + last_name); Output > JohnDoe

console.log(first_name + " " + last_name); Output > John Doe

Not sure if your question is still a question anymore.. or more of pointing out a bug in the system.