After not understanding this lesson and banging my head against it for awhile I think I understand better what is happening. I was confused because I thought this was about functions changing Main variables but I think this is about main variables changing functions. at least when i thought about it that way the example code you have to do made a lot more sense to me, and I hope this can help someone.
This lesson starts with a function to determine a tip amount, it gives me this argument example:
double get_tip(double price)
Then is asks me to create a void function with a string argument
void get_emergency_number(string emergency_number)
I was banging my head, trying to figure out why it wasnt printing the number, come to find out you have to type:
Where was this in the lesson? I think I may have missed this.
The instruction of this lesson is supper unclear, and I could not have figure it out without looking at the solution.