Some rules when using arrays:

• You need to declare the array: type, name and size
• In a function header the size is not relevant, but you still need to use the []  so that the compiler knows this is an array.
• You cannot perform any operation (=, +, -, *, /, == etc.) with the whole array:
  • ex. array1=0; // don't do that!
• You can only perform operations with EACH element of the array
  •  ex array1[k]=0; // this is ok
• Never use the array with an empty bracket
• Notice that, whenever you have an array followed by an index (in brackets) then you don't have an array, you have one ELEMENT of the array.