C++ Taskbook Level 3.6

Given an array of integers, print to the console numbers that are longer than three digits.

Given an array, output every fifth element to the console.

Given an array of strings, leave in this array only those strings that end with ".html".

Given a number, for example, like this:

int num = 12345;

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

Three arrays are given:

int arr[]1 = [1, 2, 3];
int arr[]2 = [4, 5, 6];
int arr[]3 = [7, 8, 9];

Combine these arrays into one:

int[] {1, 2, 3, 4, 5, 6, 7, 8, 9}

Given a variable with a number:

int num = 5;

Make a string containing as many zeros as specified in the variable. In our case, we get the following string:

"00000"