Can I have an array as an argument for a void function?

Using Arduino Programming Questions
1

I'm working with 17-segment (or in this case 16-segment because I'm taking out the decimal point to make things easier) alphanumeric LED displays, and want to have my code so that I can just change an array in calling the displayString function and it will interpret it and display it on the LEDs.

This is the code that defines the function:

void displayString(int string[]){
  //there are some functions in here for the 74HC595 shift
  //registers that are driving the segments as well
  clearRegisters();
  for(int i = 0; i < sizeof(string); i++){
    switch(string[i]){
      case 'A':
        //I previously defined lists named A-Z with the pins of the
        //display that should be lit for the according character
        for(int x; x < sizeof(A); x++){
          setRegisterPin(A[x] + (i * 16), HIGH);
        }
      case 'B':
        for(int x; x < sizeof(B); x++){
          setRegisterPin(B[x] + (i * 16), HIGH);
        }
      //etc...
    }
  }
  writeRegisters();
}

And here is the part where I call the function:

void loop(){
  displayString ({'A', 'B'});
  delay(10);
}

And when I verify the program, I get the following
error: expected primary-expression before '{' token

I've tried some different syntax for calling it, none of which worked, but that could easily be where the problem lies and it's the only thing I can think of that would be causing this error. So, ultimately... does anyone know the syntax for doing this?

2

Nope, you cannot pass arrays like that in C. You will have to create a variable. Now if it was defined to accept a char array, you could pass it "AB".

3

Your "string" would normally consist of chars, not ints. I suggest that you find a basic book or ebook for C syntax and read it, rather than randomly blundering around.

4

KeithRB:
Now if it was defined to accept a char array, you could pass it "AB".

This would actually be preffered over creating a list of charcters for every string, but how would I do that? Despite a bit of research I've done on the topic, I'm still kind of confused as to how C handles strings, chars, char arrays, etc. and how to use them.

5

Wait... actually I just noticed that in the void initializer I told it that the list would consist of integers, not chars. A-derpty-derp :stuck_out_tongue: I changed that and then replaced the ({"A", "B",}) with ("AB") and now it is working fine. Thanks!

6

Squirt_5432:
I just noticed that in the void initializer ...

Just to get the terminology right, it is a function initializer.

"void" is the return value (ie. nothing returned).

You call a function. You pass parameters (arguments). The function may or may not return a value. If not, it is declared "void".

Examples:

Function taking no arguments and returning nothing:

void foo (void) ...

Function taking no arguments and returning an int:

int foo (void) ...

Function taking an int argument and returning an int:

int foo (int bar) ...
7

Ahhh. Thanks, that makes much more sense!