how make an array c++ code example
Example 1: 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 2: array in c++
// Two dimensional array
int a[2][3]= {
{1, 2, 3},
{4, 5, 6}
};
cout << a[1][1]; // Output is 5
// Three dimensional array
//[2] is elements; [3] is rows in elements; [4] is column in elemnents
int a[2][3][2]= {
//Element 0
{ {1, 2},
{2, 3},
{4, 5}
},
// Element 1
{ {6, 7},
{8, 9},
{10, 11}
}
};
cout << a[0][1][1]; // Prints 3