How do I use arrays?

[uchi240]

I've been reading the tutorial for arrays. From what I got, this code int num [5] {1, 2, 3, 4, 5} is supposed to output 1 2 3 4 5. I'm not sure if I'm missing something or I'm reading it incorrectly. So, my code looks like this:

#include <iostream>

using namespace std;

int main()
{
	int num[10] {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

	cout << num[10];

	return 0;
}

It's outputting -858993460. Should it not output 0 1 2 3 4 5 6 7 8 9? I thought it would output the numbers inside the bracket. What am I not understanding?

[JLBorges]

#include <iostream>

int main()
{
    const int N = 10 ;
    const int num[N] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 } ;
    // num[0] == 0, num[1] == 1, ... upto num[N-1] == 9
    // the array num has N elements; the first is num[0], and the last is num[N-1]

    for( int i = 0 ; i < N ; ++i ) std::cout << num[i] << ' ' ;
    std::cout << '\n' ;
}

[Stormboy]

array[n] will give the nth element in the array.
If you have an array:

int num[5] = {2, 4, 6, 8, 10};

Then doing cout << num[5]; will be an error because array index starts from '0' and ends at n-1. So in this case n = 5 and the last index of the array is 4 (5-1). To access 10, you'd do cout << num[4];. To print out all the elements of an array, you need a loop, which JLBorges has already shown you.

[andy1978]

The number you are seeing there num[10] is the last value that was held in that memory address. There are no bounds checks on the array. I.e you can step over (buffer overflow) and this is a good place where bugs can happen.

Better off using vectors for arrays.