The correct answers are C and D .
The statement:
const arr = Array(5).fill(0);
creates an array with 5 elements , and every element is filled with the value 0.
So the array becomes:
[0, 0, 0, 0, 0]
A professional test should verify both important expectations:
arr.length === 5
and:
each element === 0
Option C is correct because it checks every element in the array:
arr.forEach(e = > console.assert(e === 0));
This confirms that each array element was filled with 0.
Option D is correct because it checks the array length:
console.assert(arr.length === 5);
This confirms that the array contains exactly five elements.
Option A is incorrect because the array length is not 0; it is 5.
Option B is incorrect for two reasons. First, arr[5] is outside the valid index range. The valid indexes are:
0, 1, 2, 3, 4
So:
arr[5]
returns:
undefined
Second, arr.length === 0 is false because the length is 5.
Therefore, the verified answers are C and D .
