Array BasicsΒΆ

Only local arrays (arrays declared as local variables) are discussed in this document.

  • Declaration and initialization:

    int arr[10];
int arr1[10] = {};
int arr2[] = {1, 2, 3};

    • size must be specified unless it can be inferred from initialization

    • size must be a compilation-time constant

      • int literals: 10

      • pre-defined const variable: const int SIZE = 4

      Warning

      Although variable as size is allowed with g++, it is not recommended as C++ standard does not allow that.

    1// ---- correct ----
2const int SIZE = 4;
3int arr3[SIZE];
4
5// ---- wrong ----
6int size = 4;
7int arr4[size];

  • Access the element:

    1int sum = 0;
2int arr[4] = {1, 2, 3, 4};
3cout << "The second element is " << arr[1] << endl;
4arr[1] = 12;
5cout << "Second element is set to " << arr[1] << endl;