Showcasing Simple Interface Implementation With Counters

Personal/Interfaces/Counter/src/ByFives.java

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+package src;
+
+public class ByFives implements Counter {
+
+    private int num = 5;
+    private int nextNum;
+
+    @Override
+    public int countBy() {
+        return num;
+    }
+
+    @Override
+    public int getNextNum() {
+        return nextNum += num;
+    }
+    
+}

Personal/Interfaces/Counter/src/ByFours.java

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+package src;
+
+public class ByFours implements Counter {
+
+    private int num = 4;
+    private int nextNum;
+
+    @Override
+    public int countBy() {
+        return num;
+    }
+
+    @Override
+    public int getNextNum() {
+        return nextNum += num;
+    }
+    
+}

Personal/Interfaces/Counter/src/ByOnes.java

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+package src;
+
+public class ByOnes implements Counter {
+
+    private int num = 1;
+    private int nextNum;
+
+    @Override
+    public int countBy() {
+        return num;
+    }
+
+    @Override
+    public int getNextNum() {
+        return nextNum += num;
+    }
+    
+}

Personal/Interfaces/Counter/src/ByThrees.java

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+package src;
+
+public class ByThrees implements Counter {
+
+    private int num = 3;
+    private int nextNum;
+
+    @Override
+    public int countBy() {
+        return num;
+    }
+
+    @Override
+    public int getNextNum() {
+        return nextNum += num;
+    }
+    
+}

Personal/Interfaces/Counter/src/ByTwos.java

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+package src;
+
+public class ByTwos implements Counter {
+
+    private int num = 2;
+    private int nextNum;
+
+    @Override
+    public int countBy() {
+        return num;
+    }
+
+    @Override
+    public int getNextNum() {
+        return nextNum += num;
+    }
+    
+}

Personal/Interfaces/Counter/src/Counter.java

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+package src;
+
+public interface Counter {
+    
+    int countBy();
+    int getNextNum();
+}

Personal/Interfaces/Counter/src/CounterHelper.java

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+package src;
+
+public class CounterHelper {
+    
+    private Counter[] counters;
+    private Counter userCounter = null;
+
+    public CounterHelper(Counter... counters) {
+        this.counters = counters;
+    }
+
+    public void doInteractive(int userInput) {
+
+        // Find the correct counter to count by. 
+        // When no counter is found, display error message to user and quit the program
+        for (Counter counter: counters) {
+            if (userInput == counter.countBy())
+                this.userCounter = counter;
+        }
+        if (userCounter == null) {
+            System.out.println("Counter Not Found");
+            System.exit(0);
+        }
+    }
+
+    public void displayCounter(int iterations) {
+
+        // Show the counter for the number of iterations that the user inputted
+        System.out.println();
+        for (int i = 0; i < iterations; i++) {
+            System.out.println(userCounter.getNextNum());
+        }
+    }
+}

Personal/Interfaces/Counter/src/CounterMain.java

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+package src;
+
+import java.util.Scanner;
+
+public class CounterMain {
+    public static void main(String[] args) {
+        countUp();
+        countUpInteractively();
+    }
+
+    private static void countUp() {
+        ByTwos twos = new ByTwos();
+        ByFives fives = new ByFives();
+        
+        // Display the first 5 numbers for each counter defined
+        for (int i = 0; i < 5; i++) {
+            System.out.println("Counting By " + twos.countBy());
+            System.out.println(twos.getNextNum());
+            System.out.println("Counting By " + fives.countBy());
+            System.out.println(fives.getNextNum());
+        }
+    }
+
+    private static void countUpInteractively() {
+        Scanner in = new Scanner(System.in);
+        System.out.println("Enter In The Number That You Want To Count:\n");
+        int userInput = in.nextInt();
+
+        CounterHelper helper = new CounterHelper(new ByTwos(), new ByThrees(), new ByFives());
+        helper.doInteractive(userInput);
+
+        System.out.println("Enter In The Number Of Times You Want To Count:\n");
+        int userIterations = in.nextInt();
+            
+        helper.displayCounter(userIterations);
+        in.close();
+
+        
+    }
+}