some changes

src/Engine.php

@@ -10,13 +10,13 @@
 const MIN_NUM = 1;
 const MAX_NUM = 100;
 
-function communication(array $answers, string $game): void
+function communicate(array $answers, string $game): void
 {
     $name = greeting();
     line("$game");
     foreach ($answers as $key => $value) {
         $answer = prompt("Question: $key\nYou answer");
-        if ($answer != $value) {
+        if ($answer !== $value) {
             line("'$answer' is wrong answer ;( Correct answer: '$value') \nLet's try again, $name!");
             return;
         } else {
@@ -26,7 +26,7 @@ function communication(array $answers, string $game): void
     line("Congratulations, $name!");
 }
 
-function arrayNumbers(): array
+function getArrayNumbers(): array
 {
     $numbers = [];
     for ($i = 1; $i <= ROUND; $i++) {

src/Games/Calc.php

@@ -2,7 +2,7 @@
 
 namespace BrainGames\Games\Calc;
 
-use function BrainGames\Engine\communication;
+use function BrainGames\Engine\communicate;
 
 use const BrainGames\Engine\ROUND;
 use const BrainGames\Engine\MIN_NUM;
@@ -19,21 +19,18 @@ function runCalc(): void
         $operator = $signs[array_rand($signs)];
         $answers["$first $operator $second"] = calculate($first, $second, $operator);
     }
-    communication($answers, $game);
+    communicate($answers, $game);
 }
-function calculate(int $num1, int $num2, string $operation): int
+function calculate($first, $second, $operator): string
 {
-    $result = 0;
-    switch ($operation) {
+    switch ($operator) {
         case '+':
-            $result = $num1 + $num2;
-            break;
+            return $first + $second;
         case '-':
-            $result = $num1 - $num2;
-            break;
+            return $first - $second;
         case '*':
-            $result = $num1 * $num2;
-            break;
+            return $first * $second;
+            default:
+                break;
     }
-    return $result;
 }

src/Games/Even.php

@@ -2,21 +2,21 @@
 
 namespace BrainGames\Games\Even;
 
-use function BrainGames\Engine\communication;
-use function BrainGames\Engine\arrayNumbers;
+use function BrainGames\Engine\communicate;
+use function BrainGames\Engine\getArrayNumbers;
 
 function runEven()
 {
     $game = 'Answer "yes" if the number is even, otherwise answer "no".';
     $answers = [];
-    foreach (arrayNumbers() as $number) {
+    foreach (getArrayNumbers() as $number) {
         if (isEven($number)) {
             $answers[$number] = 'yes';
         } else {
             $answers[$number] = 'no';
         }
     }
-    communication($answers, $game);
+    communicate($answers, $game);
 }
 
 function isEven(int $num): bool

src/Games/GCD.php

@@ -1,8 +1,8 @@
 <?php
 
-namespace BrainGames\Games\GCD;
+namespace BrainGames\Games\Gcd;
 
-use function BrainGames\Engine\communication;
+use function BrainGames\Engine\communicate;
 
 use const BrainGames\Engine\ROUND;
 use const BrainGames\Engine\MIN_NUM;
@@ -15,12 +15,12 @@ function runGcd(): void
     for ($i = 1; $i <= ROUND; $i++) {
         $first = mt_rand(MIN_NUM, MAX_NUM);
         $second = mt_rand(MIN_NUM, MAX_NUM);
-        $answers["$first $second"] = nod($first, $second);
+        $answers["$first $second"] = getNod($first, $second);
     }
-    communication($answers, $game);
+    communicate($answers, $game);
 }
 
-function nod(int $x, int $y)
+function getNod(int $x, int $y): string
 {
     while ($x !== 0 && $y !== 0) {
         if ($x >= $y) {

src/Games/Prime.php

@@ -2,21 +2,21 @@
 
 namespace BrainGames\Games\Prime;
 
-use function BrainGames\Engine\arrayNumbers;
-use function BrainGames\Engine\communication;
+use function BrainGames\Engine\getArrayNumbers;
+use function BrainGames\Engine\communicate;
 
 function runPrime(): void
 {
     $game = 'Answer "yes" if given number is prime. Otherwise answer "no".';
     $answers = [];
-    foreach (arrayNumbers() as $number) {
+    foreach (getArrayNumbers() as $number) {
         if (isPrime($number)) {
             $answers[$number] = 'yes';
         } else {
             $answers[$number] = 'no';
         }
     }
-    communication($answers, $game);
+    communicate($answers, $game);
 }
 
 function isPrime(int $num): bool

src/Games/Progression.php

@@ -2,7 +2,7 @@
 
 namespace BrainGames\Games\Progression;
 
-use function BrainGames\Engine\communication;
+use function BrainGames\Engine\communicate;
 
 use const BrainGames\Engine\ROUND;
 use const BrainGames\Engine\MIN_NUM;
@@ -13,16 +13,16 @@ function runProgression(): void
     $game = 'What number is missing in the progression?';
     $answers = [];
     for ($i = 1; $i <= ROUND; $i++) {
-        $numbers = slicer();
+        $numbers = getSlice();
         $randomSym = mt_rand(0, (count($numbers) - 1));
         $correctAnswer = $numbers[$randomSym];
         $numbers[$randomSym] = '..';
         $numbersString = implode(' ', $numbers);
         $answers[$numbersString] = "$correctAnswer";
     }
-    communication($answers, $game);
+    communicate($answers, $game);
 }
-function slicer(): array
+function getSlice(): array
 {
     $num = [];
     $num[] = 0;