Passing an array by reference

Solution 1:

It's a syntax for array references - you need to use (&array) to clarify to the compiler that you want a reference to an array, rather than the (invalid) array of references int & array[100];.

EDIT: Some clarification.

void foo(int * x);
void foo(int x[100]);
void foo(int x[]);

These three are different ways of declaring the same function. They're all treated as taking an int * parameter, you can pass any size array to them.

void foo(int (&x)[100]);

This only accepts arrays of 100 integers. You can safely use sizeof on x

void foo(int & x[100]); // error

This is parsed as an "array of references" - which isn't legal.

Solution 2:

It's just the required syntax:

void Func(int (&myArray)[100])

^ Pass array of 100 int by reference the parameters name is myArray;

void Func(int* myArray)

^ Pass an array. Array decays to a pointer. Thus you lose size information.

void Func(int (*myFunc)(double))

^ Pass a function pointer. The function returns an int and takes a double. The parameter name is myFunc.

Solution 3:

It is a syntax. In the function arguments int (&myArray)[100] parenthesis that enclose the &myArray are necessary. if you don't use them, you will be passing an array of references and that is because the subscript operator [] has higher precedence over the & operator.

E.g. int &myArray[100] // array of references

So, by using type construction () you tell the compiler that you want a reference to an array of 100 integers.

E.g int (&myArray)[100] // reference of an array of 100 ints