LAMP Assessment

Write a PHP function that takes a sentence and returns the word with the most vowels.

Answer:

<?php
function mostVowels($sentence) {
    $sentence = preg_replace("/[^A-Za-z0-9 ]/", '', $sentence);
    $words = explode(' ', $sentence);
    $maxWord;
    $maxCount = 0;
    foreach($words as $word) {
        preg_match_all('/[aeiou]/i',$word, $matches);
        $curCount = count($matches[0]);
        if ($curCount > $maxCount) {
            $maxCount = $curCount;
            $maxWord = $word;
        }
    }
    return $maxWord;
}

What is the final output of the below code?

<?php
function changeName(&$newName) {
  $newName = 'blah';
}
function changeAgain($newName) {
  $newName = 'Keith';
}
$myName = 'Keith';
changeName($myName);
changeAgain($myName);
echo $myName;

Answer: It echos 'blah', changeName takes a reference and changeAgain passes by value.

How would you approach refactoring the following class in order to make it more testable and clean?

<?php
class SomeImportantClass {
  public function someFunction($someParameter, $otherParameter) {
    $someData = SomeSingleton->getInstance()->calculateStuff($otherParameter);


    $result = ... // operate on $someData and $someParameter


    return $result;

  }
}

Answer:

<?php
class SomeImportantClass {
  protected $singleton;
  public function __construct($singleton=SomeSingleton) {
    $this->singleton = $singleton;
  }
  public function someFunction($someParameter, $otherParameter) {
    $someData = $this->singleton->getInstance()->calculateStuff($otherParameter);


    $result = ... // operate on $someData and $someParameter


    return $result;

  }
}

As a deeper answer, since a singleton is being used in this class, when writing tests either the singleton should implement a reset function for the test setup and teardown or reflection api can be used to reinstance the singleton. In general though, singleton pattern makes for difficult testing since you are spreading what is effectively a global scope all over the code.

Write a PHP function that returns true if a number is prime and false otherwise.

Answer:

<?php
function isPrime($number) {
  for ($i=2; $i < $number; $i++) {
    if($number % $i == 0) {
      return false;
    }
  }
  return true;
}

Consider the following MySQL database schema:

items	orders	delivery_address
order_id item_name quantity 100 Shirt 1 101 Shirt 1 102 Hat 1 103 Jacket 1 101 Hat 2 104 Hat 3 103 Pants 2 103 Shirt 2	id date amount 100 2016-12-04 $5.00 101 2016-12-27 $30.00 102 2017-01-06 $25.00 103 2017-01-14 $6.00 104 2017-01-14 $13.00	order_id address 100 123 Main St 103 456 First Ave 104 789 Central Blvd

Write a query that retrieves order IDs that contained a Hat, and include the delivery address if provided

Answer:

SELECT id, address FROM orders
JOIN items ON orders.id = items.order_id
LEFT JOIN delivery_address ON orders.id = delivery_address.order_id
WHERE item_name = 'Hat';

Write a query that retrieves each order and the total count of all items sold for each order. Sort the results per orders having sold the highest counts of “distinct” items

Answer:

SELECT i.order_id, i.sum AS total_count
FROM (
  SELECT order_id, count(order_id), sum(quantity) FROM items
	GROUP BY order_id
	ORDER BY count DESC
) i

Consider the two arrays, $carMakeCount and $carMakeType. Write a function that maps both datasets and returns an array having a structure identical to $exampleMapped:

<?php
$carMakeCount = ['lexus' => 4, 'bmw' => 2, 'mercedes' => 5];
$carMakeType = ['suv'=>'lexus', 'coupe'=>'mercedes', 'sedan'=>'bmw'];

$exampleMapped = [
	'lexus has 4 suv',
	'bmw has 2 sedan',
	'mercedes has 5 coupe'
];

Answer:

<?php
function exampleMap($carMakeCount, $carMakeType) {
	return array_map(function ($make, $type) {
	  return "$make has $carMakeCount[$make] $type";
	}, $carMakeType, array_keys($carMakeType));
}

Design a set of PHP classes in an object oriented manner to model various shapes. Start with a Shape class where a shape is any two dimensional figure that has the following characteristics: name, perimeter, area.

Answer:

<?php
interface IShape {
  public function area();
  public function perimeter();
}

interface IStringable {
  public function toString();
}

class Shape {
  protected $name;
  public function __construct($name) {
    $this->name = $name;
  }
  public function name() {
    return $this->name;
  }
}

Define a Circle that share the same characteristics defined for a Shape

<?php
class Rectangle extends Shape implements IShape, IStringable {
  protected $width;
  protected $height;

  public function __construct($width, $height, $name="Rectangle") {
    parent::__construct($name);
    $this->width = $width;
    $this->height = $height;
  }

  public function area() {
    return $this->width * $this->height;
  }
  public function perimeter() {
    return 2 * ($this->width + $this->height);
  }
  public function toString() {
    return "[$this->name] width: $this->width, height: $this->height";
  }
}

class Circle extends Shape implements IShape, IStringable {
  protected $radius;

  public function __construct($radius, $name="Circle") {
    parent::__construct($name);
    $this->radius = $radius;
  }

  public function area() {
    return $this->radius * $this->radius * pi();
  }
  public function perimeter() {
    return 2 * pi() * $this->radius;
  }
  public function toString() {
    return "[$this->name] radius: $this->radius";
  }
}