staticmembers

src/main/java/com/amigoscode/_2_developers/_13_staticmembers/StaticExercises.java

@@ -11,63 +11,80 @@ public class StaticExercises {
 
     // TODO: 1 - Create a private static int field called 'counter' initialized to 0.
     //  This field is shared among ALL instances of StaticExercises.
+    private static int counter = 0;
 
     // An instance field for comparison (already provided)
     private String instanceName;
 
     // TODO: 2 - Create a constructor that takes a String name parameter.
     //  Assign the name to instanceName.
     //  Increment the static counter by 1 each time a new instance is created.
+    public StaticExercises(String name) {
+        this.instanceName = name;
+        counter++;
+    }
 
 
     // TODO: 3 - Create a public static method: int getCount()
     //  Returns the current value of counter.
     //  Note: static methods can only access static fields, not instance fields.
+    public static int getCount() {
+        return counter;
+    }
 
 
     // TODO: 4 - Create a public static utility method: double celsiusToFahrenheit(double celsius)
     //  Returns the temperature in Fahrenheit using the formula: (celsius * 9/5) + 32.
     //  Utility methods are a common use case for static methods — they don't need
     //  any instance state.
+    public static double celsiusToFahrenheit(double celsius) {
+        return (celsius * 9/5) + 32;
+    }
 
 
     // TODO: 5 - Create a public method (non-static): String getInfo()
     //  Returns "Instance: <instanceName>, Total instances: <counter>"
     //  This demonstrates that instance methods can access BOTH instance and static fields.
     //  A static method could NOT access instanceName.
+    public String getInfo() {
+        return "Instance: " + instanceName + ", Total instances: " + getCount();
+    }
 
 
     // TODO: 6 - Create a public static factory method: StaticExercises createDefault()
     //  Returns a new StaticExercises instance with the name "Default".
     //  Factory methods are static methods that create and return instances.
     //  They are an alternative to constructors and can have descriptive names.
+    public static StaticExercises createDefault() {
+        return new StaticExercises("Default");
+    }
 
 
     public static void main(String[] args) {
         // Uncomment the code below after completing all TODOs:
 
-        // System.out.println("=== Static Counter ===");
-        // System.out.println("Count before creating instances: " + getCount());
+         System.out.println("=== Static Counter ===");
+         System.out.println("Count before creating instances: " + getCount());
 
-        // StaticExercises obj1 = new StaticExercises("First");
-        // StaticExercises obj2 = new StaticExercises("Second");
-        // StaticExercises obj3 = new StaticExercises("Third");
+         StaticExercises obj1 = new StaticExercises("First");
+         StaticExercises obj2 = new StaticExercises("Second");
+         StaticExercises obj3 = new StaticExercises("Third");
 
-        // System.out.println("Count after creating 3 instances: " + getCount());
+         System.out.println("Count after creating 3 instances: " + getCount());
 
-        // System.out.println("\n=== Static Utility Method ===");
-        // System.out.println("0°C = " + celsiusToFahrenheit(0) + "°F");
-        // System.out.println("100°C = " + celsiusToFahrenheit(100) + "°F");
-        // System.out.println("37°C = " + celsiusToFahrenheit(37) + "°F");
+         System.out.println("\n=== Static Utility Method ===");
+         System.out.println("0°C = " + celsiusToFahrenheit(0) + "°F");
+         System.out.println("100°C = " + celsiusToFahrenheit(100) + "°F");
+         System.out.println("37°C = " + celsiusToFahrenheit(37) + "°F");
 
-        // System.out.println("\n=== Static vs Instance ===");
-        // System.out.println(obj1.getInfo());
-        // System.out.println(obj2.getInfo());
-        // Note: getCount() is called on the class, getInfo() is called on an instance
-        // StaticExercises.getCount() works, but StaticExercises.getInfo() does NOT compile
+         System.out.println("\n=== Static vs Instance ===");
+         System.out.println(obj1.getInfo());
+         System.out.println(obj2.getInfo());
+//         Note: getCount() is called on the class, getInfo() is called on an instance
+//         StaticExercises.getCount() works, but StaticExercises.getInfo() does NOT compile
 
-        // System.out.println("\n=== Static Factory Method ===");
-        // StaticExercises defaultObj = StaticExercises.createDefault();
-        // System.out.println(defaultObj.getInfo());
+         System.out.println("\n=== Static Factory Method ===");
+         StaticExercises defaultObj = StaticExercises.createDefault();
+         System.out.println(defaultObj.getInfo());
     }
 }