Question

I have written this piece of code:

#include <iostream>

using namespace std;

double function(int i)
{
    static int Array[5] = {0};

    for(int j = i ; j <= i ; j++)
    {
        Array[j+1] = Array[j]+1;
    }
    return Array[i+1];
}

int main()
{
    for(int i = 0 ; i <= 4 ; i++)
    {
        cout << function(i) << endl;
    }
    return 0;
}

Which outputs 1,2,3,4,5

I am wondering why elements of Array at each call of function(i) doesn’t become zero despite this piece of code :

static int Array[5] = {0};

Answer 1

The array is static, which means it gets initialized just once (the first time function is called). It keeps its existing items thereafter. If you remove the static keyword you will get 1, 1, 1, 1, 1 instead.

By the way, the for loop inside function is redundant (it’s guaranteed to only execute exactly once).