Kata

Create a function (a method in Ruby, an extension method in C#) every which returns every nth element of an array.

Usage

• With one argument, every(array) returns every element of the array.

• With two arguments, every(array, interval) it returns every intervalth element.

• With three arguments, every(array, interval, start_index) returns every intervalth element starting at index start_index.

Examples

every([0,1,2,3,4])     -> [0,1,2,3,4]
every([0,1,2,3,4],1)   -> [0,1,2,3,4]
every([0,1,2,3,4],2)   -> [0,2,4]
every([0,1,2,3,4],3)   -> [0,3]
every([0,1,2,3,4],3,1) -> [1,4]

Notes

Test cases:

• interval will always be a positive integer (but may be larger than the size of the array).
• start_index will always be within the bounds of the array.

Once you have completed this kata, try the advanced version (http://www.codewars.com/kata/every-nth-array-element-advanced) which allows negative intervals and unbounded start_indexes