PHP Taskbook Level 3.6

Задание 1

Given an array of numbers, remove numbers from it that have more than three digits.

Задание 2

Given a number, for example, like this:

php$num = 12345;

Check that all digits of this number are greater than zero.

Задание 3

Given some array, for example, like this:

php[123, 456, 789]

Merge all the elements of this array into one array, splitting them character by character:

php[1, 2, 3, 4, 5, 6, 7, 8, 9]