sizeof() array c++ code example

Example 1: c++ get length of array

int arr[5];
int len = sizeof(arr) / sizeof(arr[0]);
// returns 5

Example 2: 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 3: array length 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 4: length of array c++

#include <iostream>
using namespace std;
int main() {
   int arr[5] = {4, 1, 8, 2, 9};
   int len = sizeof(arr);
   cout << "The length of the array is: " << len;
   return 0;
}