[C++] Chapter 2: Types

 

1. Function types

a) return type: int, arg type: double (function)

int func(double)

int (double)

 

b) return type: &int[2][3], arg type: double (function)

int (*func(double))[2][3]

int (*(double))[2][3]

 

c) return type: function pointer of (b), arg type: double (function pointer)

int (*(*)(double))[2][3]

 

d) return type: int[2][3], arg type: vector<double> (function)

int (std::vector<double>)[2][3]

 

2. typedef

typedef int(*ARRAY2D_POINTER)[2][3];

above defines "ARRAY2D_POINTER" as int* [2][3]

 

3. Pointer

void main() {

	int* arr[2];
	int x = 1;
	int y = 2;
	arr[0] = &x;
	arr[1] = &y;
	cout << *arr[0] << endl;

	int** brr = new int*[2];
	brr[0] = &x;
	brr[1] = &y;
	cout << *brr[0] << endl;
	delete[] brr;

}

 

4. const

void main() {

	// all elements are const
	const int arr[3] = { 1, 2, 3 };

	// *cp is const
	int a = 3;
	const int* cp;
	cp = &a;

	// cp is const
	int* const cp = &a;


}

 

5. auto

void main() {

	vector<int> v = { 1, 2, 3 };
	int sum = 0;
	// auto : vector<int>::iterator
	for (auto it = v.begin(); it != v.end(); it++) {
		sum += *it;
	}
	cout << sum << endl;

}