Challenge-7.php

<?php


/*
Challenge 7: Snail print an array

Rules::
1. No Exceptions or PHP errors / warnings notices allowed
2. No redefining the test arrays.
3. Your function must be able to cope with n by n arrays as input
4. Your output must be a single string


Hints:
1. Recursion might be your option. See 3.
2. PHP has array functions. I highly suggest them :)
3. Recursion might be your option. See 1.

Explanation:

Assume you have an n by n array that looks like such:

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

Snail printing is where you iterate through the array, and print the values that are on the outermost edge, working inwards.
So for the above array, your output would be 123698745

Going larger, a 4x4 example:

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

Your output would be 1234862345956778
*/


function snail($input)
{
// Start editing here

//end editing here
    return $output;
}

$testArrayOne = [[1, 2, 3], [4, 5, 6], [7, 8, 9]];

$result = snail($testArrayOne);

if($result != '123698745')
{
    die('Failure of output: ' .$result );
}

$testArrayTwo = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 8, 7, 6], [5, 4, 3, 2]];


$result = snail($testArrayTwo);

if($result != '1234862345956778')
{
    die('Failure of output: ' .$result );
}