Size of Array

Question

https://code.sololearn.com/c8mf0UjIjVTU/?ref=app
read the code give and can someone tell why we need to know the size of array and where we need that and how this array size is 28 ?

Answer 1

To get number of elements contained by array , you must know size of array.

Here,
int n = sizeof(arr)/sizeof(arr[0]);

n is number of elements which you get 7.

n = sizeof array 28 / size of one element 4 = 7

This n you can use to set condition while you are iterating on array using loop.

see below code where I used n to iterate over arr using for loop to print each element of an array.
#include <iostream>
using namespace std;

int main() {
int arr[] = {5, 2, 42, 6, 1, 3, 2};
int n = sizeof(arr)/sizeof(arr[0]);

for (int i = 0; i < n ; i++)
cout <<" "<<arr[i];
cout <<endl;
return 0;
}

This just an example but in real you can do any operation on array elements like above.

Answer 2

hey i got it the array has 7 elements and each elements are integer and one integer sizeof 4 so 4×7=28; but still haven't gotten where this used