length of integer array C++ code example

Example 1: array length c++

#include <iostream>
using namespace std;

#define size(type) ((char *)(&type+1)-(char*)(&type))

int main(){
  int arr[5] = {1, 2, 3, 4, 5};
  cout << size(arr) / size(arr[0]) << endl; //returns 5
  //alternatively
  cout << sizeof(arr) / sizeof(int) << endl; //returns 5
}

Example 2: length of array c++

// array::size
#include <iostream>
#include <array>

int main ()
{
  std::array<int,5> myints;
  std::cout << "size of myints: " << myints.size() << std::endl;
  std::cout << "sizeof(myints): " << sizeof(myints) << std::endl;

  return 0;
}

Example 3: length of each number in array in c++

const int SIZE = 9;
	int arr[SIZE], arr2[SIZE];
	cout << "Enter numbers: \n";
	for (int i = 0; i < SIZE; i++)
		cin >> arr[i];
	for (int i = 0; i < SIZE; i++)
		cout << arr[i] << "\t";
	cout << endl;
	
	int count, number;
	for (int i = 0; i < SIZE; i++)
	{
		count = 0;
		number = arr[i];
		do
		{
			++count;
			number /= 10;
		} while (number);
		arr2[i] = count;
	}
	for (int i = 0; i < SIZE; i++)
		cout << arr2[i] << "\t";
	cout << endl;