array declaration c++ code example

Example 1: how to make an array c++

int foo [] = { 16, 2, 77, 40, 12071 };

Example 2: array declaration c++

int foo [5];

Example 3: number of elements in c++ array

#include <iostream>
using std::cout;

int a[] = { 1, 2, 3, 4, 5 };
int counta()
  {
  return sizeof( a ) / sizeof( a[ 0 ] );  // works, since a[] is an array
  }

int countb( int b[] )
  {
  return sizeof( b ) / sizeof( b[ 0 ] );  // fails, since b[] is a pointer
  }

Example 4: create array c++

int foo[5] = {0};

Example 5: arrays in c++

#include <iostream>
#include <array> //for using std::array

int main()
{

	int example[5];//array on stack
	int* another = new int[5];//array on heap
	delete[] another;//freeing up memory on heap
	example[0] = 1;
	example[1] = 2;
	example[2] = 3;
	example[3] = 4;
	for (int i = 0; i < 5; i++) {
		example[i] = 2;
	}
	int* ptr = example;//arrays are just pointers to the begining of the block of memory
	example[2] = 5;
	*(ptr + 2) = 6;//adding 4+4 bytes to ptr
	std::cout << example[2] << std::endl;//output => 6
	*(int*)((char*)ptr + 8) = 8;//adding 8 bytes to ptr using ptr arithmetic
	std::cout << example[2] << std::endl;//output => 8
	//std::array provide some additional functionality like bounce checking size checking but do have a performance overhead
	std::array<int,5> stda;//creating an array named stda of int 5 size
	std::cout << stda.size() << std::endl;//will output size of std::array ,output =>5   
    std::cin.get();
}

Example 6: how to make a array in c++

// datatype var_name[howmuch value you need to store] = {values, values}
int a[5] = {1, 2 3, 4, 5};