Thread: Error: I value required as left operand of assignment

I am getting this error when compiling my program with quincy:
Error: I value required as left operand of assignment
Tthe program is meant to calculate how much parking costs based on the amount of hours in a park and what type of vehicle it is. the error is coming from my function definitions which i have just started to add in.

Code:

float calcCarCost (char vehicletype, int time, float car)
{

 if ((time > MINTIME) && (time <= 3)) 
 calcCarCost =( CAR * time );
 
     
}

the error is on line 72 which is:
calcCarCost =( Car * time);

i should probably point out CAR is already defined as a constant with a numerical value given and time is previously asked to be input in when the program runs.

i am pretty new to programming in general which is probably pretty obvious by now and im just wondering what is causing the problem. If any more information is needed just ask. Thanks in advance

Well lexically that's just the syntax for multiplication, and it's the lack of being able to successfully look up the symbol for CAR that is the semantic problem.

O_o

This is C++; the statement in isolation can be almost anything and imply anything at all. Here, if you missed the note that `CAR' is a constant numeric value, the syntax is almost certainly invalid. (You also apparently missed the note because `CAR' and `car' are said to be intentionally two different things.) It can easily be assumed that `CAR' is a type also implying problems with case consistency or misunderstanding how to return an instance of a `CAR' object.

[Edit]
I'll explain for those who don't appreciate the problems of this form of mixed declarations and expressions.

That is the syntax for a few different things. (Most obviously, pointer declaration syntax and the multiplication operator.)

What it is semantically depends on "LHS" and "RHS".

If `CAR' is a type, the syntax is a declaration and semantically you've declared a pointer to a `CAR' type. (With C++, it doesn't matter what `time' is in this case because the compiler will try to treat it as a declaration.)

If `CAR' is a variable and `time' is a variable or literal alias, the syntax is the multiplication operator and semantically you've done whatever is appropriate to the types involved. (So, preferably, some form of multiplication is involved.)

If `CAR' is a variable and `time' is not a variable or literal alias, the syntax is meaningless and the result semantically meaningless.

This all before templates and the C inherited preprocessed are involved, but at that point you have to expand everything so isn't interesting to this case. To be clear, what the expression may actually be can depend on how the template was instantiated or what problems may be related to macro.
[/Edit]

Soma

Yeah, I know, easy to forget which forum you're in around here. Maybe we need a different colour scheme or something.

O_o

I guess I need to confess that I tripped over myself.

I get tired of writing out the relevant C family so just listed C++.

When I came back to explain I thought it was the C++ board because of my own post. ;_;

Soma

yeah thanks i fixed all the problems and it works fine now. Thanks to everyone who gave some input