add new class

Author: Pavel Makarov

2_Iterator.java

@@ -37,8 +37,8 @@ public static void main(String[] args) {
             System.out.println(iterator.value());
         }
 
-        for ( ; !iterator.over(); iterator.prev() ) {
-            System.out.println(iterator.value());
-        }
+        // for ( ; !iterator.over(); iterator.prev() ) {
+        //     System.out.println(iterator.value());
+        // }
     }
 }

1_CollectionMain.java renamed to CollectionMain.java

@@ -0,0 +1,44 @@
+public class Iterator {
+    private int first;
+    private int step;
+    private int index;
+
+    public Iterator(int first, int step, int index) {
+        this.first = first;
+        this.step = step;
+        this.index = index;
+    }
+    public void next() {
+        if ( over() ) {
+            return;
+        }
+        first += step;
+        index -= 1;
+    }
+    public void prev() {
+        if ( over() ) {
+            return;
+        }
+        first -= step;
+        index -= 1;
+    }
+    public boolean over() {
+        return index == 0;
+    }
+    public int value() {
+        return first;
+    }
+    
+
+    public static void main(String[] args) {
+        Iterator iterator = new Iterator(10, 2, 4);
+
+        for ( ; !iterator.over(); iterator.next() ) {
+            System.out.println(iterator.value());
+        }
+
+        for ( ; !iterator.over(); iterator.prev() ) {
+            System.out.println(iterator.value());
+        }
+    }
+}

3_ExceptionExample.java renamed to ExceptionExample.java

@@ -0,0 +1,23 @@
+public class Iterator_ {
+    private int first;
+    private int step;
+    private int index;
+
+    public Iterator_(int first, int step, int index);
+    public void next();
+    public void prev();
+    public boolean over();
+    public int value();
+
+    public static void main(String[] args) {
+        Iterator_ iterator = new Iterator_(10, 2, 4);
+
+        for ( ; !iterator.over(); iterator.next() ) {
+            System.out.println(iterator.value());
+        }
+
+        for ( ; !iterator.over(); iterator.prev() ) {
+            System.out.println(iterator.value());
+        }
+    }
+}