PHP should be upgraded to version 8.0

the Elvis operator is not portable though

:)

You should defer calculations of sqrt as late as you can (not do it right away), trying to return as early as you can, and considering various edge cases.

Cool! I haven't seen a ternary used like this.

What does this kata add that other kata's about primes haven't done before?

I enjoyed everything, it was an awesome challenge.

ready

ready

ready

Very confusing description. (Copy paste the markdown)

Task :

Hello, warrior!

In this kata, you need to complete the function sum_not_prime, which takes two parameters :

• max_prime.
• max_num.
  and must return an array of length max_num where for each index 0 <= i <= max_num -1 :

array[i] = \sum_{p \, \le max-prime, p | i} p

Example :

• sum_not_prime(10, 15)
  The primes that need to be considered : $2$, $3$, $5$ and $7$.

  1. With $p=2$ : [0, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2]
  2. With $p=3$ : [0, 0, 2, 3, 2, 0, 2+3=5, 0, 2, 3, 2, 0, 2+3=5, 0, 2]
  3. With $p=5$ : [0, 0, 2, 3, 2, 5, 5, 0, 2, 3, 2+5=7, 0, 5, 0, 2]
  4. With $p=7$ : [0, 0, 2, 3, 2, 5, 5, 7, 2, 3, 7, 0, 5, 0, 2+7=9]

  Final result : [0, 0, 2, 3, 2, 5, 5, 7, 2, 3, 7, 0, 5, 0, 9]

Note :

Although 0 % prime == 0, index 0 is always excluded from being updated.

The description isn't clear. I needed to study the example pretty carefully to figure out what needed to be done. For one thing, it should be clarified that the prime divisor is never added to the element at index 0, despite the fact that 0 % [prime] equals 0.

• Random tests should be put inside the actual tests suite, not Preloaded.
• There should be some fixed tests in there, too