3 — עובדים עם האובייקטים

                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:text="Deserialize to Pet[]" />
+            <Button
+                android:id="@+id/showAvailable"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="Show available objects" />
+            <Button
+                android:id="@+id/showAll"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="Show all objects" />
+            <Button
+                android:id="@+id/renameFirst"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="Rename first object to Pixel" />
             <TextView
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"

 import com.google.gson.Gson;
 import com.google.gson.JsonParseException;
 
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Scanner;
 import java.util.Map;

         binding.getPets.setOnClickListener(v -> getPets());
         binding.loadDemo.setOnClickListener(v -> loadDemo());
         binding.parsePets.setOnClickListener(v -> parsePets());
+        binding.showAvailable.setOnClickListener(v -> showAvailable());
+        binding.showAll.setOnClickListener(v -> renderPets(pets));
+        binding.renameFirst.setOnClickListener(v -> renameFirst());
     }
 
     /** Fetches JSON as text; no Java Pet objects are created here. */

         }
     }
 
+    /** Selects existing objects by their status; no JSON processing is needed. */
+    private void showAvailable() {
+        ArrayList<Pet> available = new ArrayList<>();
+        for (Pet pet : pets) {
+            if ("available".equals(pet.status)) available.add(pet);
+        }
+        renderPets(available.toArray(new Pet[0]));
+    }
+
+    /** Mutates an object in memory while leaving both JSON text areas untouched. */
+    private void renameFirst() {
+        if (pets.length == 0) {
+            binding.objectStatus.setText("Deserialize some animals first");
+            return;
+        }
+        pets[0].name = "Pixel";
+        renderPets(pets);
+    }
+
     /** Displays object fields; this method never reads or parses JSON. */
     private void renderPets(Pet[] animals) {
         binding.petTable.removeAllViews();