Not understanding array in calculation

Question

I did not understand ( Array in ca
Calculation ) lesson.

It is not clear to me .

Can anyone help?

Answer 1

It is just another example how to use arrays. While the other examples set or changed individual "compartments" of the array, the calculation example uses a variable "sum" as accumulator to reduce an array of numbers to its total sum.

int arr[] = {11, 35, 62, 555, 989};
int sum = 0;

for (int x = 0; x < 5; x++) {
sum += arr[x];
}

cout << sum << endl;

Such scenarioes may well arise. For instance: sample data. Read them into an array and later work with the array to calculate some statistical information [like mean value, median, deviation and the like]. Then you need to perform operations over an entire array of variable size of values.