arrays.cpp

/*
 * Arrays.cpp
 *
 *  Created on: Jan 4, 2012
 *      Author: behnam
 */
#include <algorithm>
#include <array>
#include <iostream>
#include <iterator>
#include <string>

// this one expect exactly 3x4
void foo(int a[4][3]) {}

// we can omit (only) the first size dimension(the most left one)
void foo(int a[][3], int size) {}

void foo(int *a[10], int size) {}

void foo(int **a, int m, int n) {}

void sendingArraytoFunctions() {
  int array[2][3];
  foo(array, 3);

  int *p_array[10];
  for (int i = 0; i < 10; i++)
    p_array[i] = new int[4];
  foo(p_array, 4);

  int **pp_array;
  int m, n;

  m = 4;
  n = 5;

  pp_array = new int *[n];
  for (int i = 0; i < m; i++)
    pp_array[i] = new int[n];

  int first2DArray[3][5] = {
      {
          1,
          2,
          3,
          4,
          5,
      }, // row 0
      {
          6,
          7,
          8,
          9,
          10,
      },                   // row 1
      {11, 12, 13, 14, 15} // row 2
  };

  foo((int **)&first2DArray[0][0], 3, 5);
}

void accessingArrayElements() {
  int array[] = {1, 2, 3, 4, 5};
  std::cout << "sizeof(array)=" << sizeof(array)
            << std::endl; // prints 20 (5 elements * 4 bytes each)
  const int number_of_elemenets = sizeof(array) / sizeof(int);
  std::cout << "number of elemenets = " << number_of_elemenets << std::endl;

  // These are equal:
  // array<=>&array[0]
  // array+index<=>&array[index]
  std::cout << "*array=" << *array << std::endl;
  std::cout << "*(array+2)=" << *(array + 2) << std::endl;

  for (int *p = array; p != array + number_of_elemenets; p++) {
    std::cout << *p << std::endl;
  }
}

void cppArrayExample() {
  // std::array is a container that encapsulates fixed size arrays. // (not
  // needed in C++11 after the revision and in C++14 and beyond)
  std::array<int, 3> a2 = {1, 2, 3};
  std::array<std::string, 2> a3 = {std::string("a"), "b"};

  // container operations are supported
  std::sort(a2.begin(), a2.end());
  std::reverse_copy(a2.begin(), a2.end(),
                    std::ostream_iterator<int>(std::cout, " "));

  std::cout << '\n';
}

struct Foo {};

void checkingIsArray() {
  const char *s = "Behnam";
  std::cout << std::boolalpha;
  std::cout << std::is_array<Foo>::value << '\n';
  std::cout << std::is_array<Foo[]>::value << '\n';
  std::cout << std::is_array<Foo[3]>::value << '\n';
  std::cout << std::is_array<float>::value << '\n';
  std::cout << std::is_array<int>::value << '\n';
  std::cout << std::is_array<int[]>::value << '\n';
  std::cout << std::is_array<int[3]>::value << '\n';
  std::cout << std::is_array<std::array<int, 3>>::value << '\n';
}

int main(int argc, char *argv[]) {
  checkingIsArray();
  return 0;
}