Use filter first to keep even numbers, then use map to square them. Print the result as comma-separated values.

Array:
[1, 2, 3, 4, 5, 6, 7, 8]

Expected output:
4,16,36,64

Steps:
1. Create an evens variable by filtering the array to keep only even numbers
2. Create a squared variable by mapping evens to num * num
3. Print squared with join(',')