From 3625bc6cbddd473659b3f584c0dbec515c07c786 Mon Sep 17 00:00:00 2001
From: Kamal Wickramanayake <kamal@inbox.lk>
Date: Sat, 21 Feb 2026 20:32:52 +0530
Subject: Added oop/interfaces sample code

---
 oop/11-interfaces/.gitignore           |  1 +
 oop/11-interfaces/BasicCalculator.java | 15 +++++++++++++++
 oop/11-interfaces/Calculator.java      | 24 ++++++++++++++++++++++++
 oop/11-interfaces/CalculatorTest.java  |  9 +++++++++
 4 files changed, 49 insertions(+)
 create mode 100644 oop/11-interfaces/.gitignore
 create mode 100644 oop/11-interfaces/BasicCalculator.java
 create mode 100644 oop/11-interfaces/Calculator.java
 create mode 100644 oop/11-interfaces/CalculatorTest.java

(limited to 'oop')

diff --git a/oop/11-interfaces/.gitignore b/oop/11-interfaces/.gitignore
new file mode 100644
index 0000000..6b468b6
--- /dev/null
+++ b/oop/11-interfaces/.gitignore
@@ -0,0 +1 @@
+*.class
diff --git a/oop/11-interfaces/BasicCalculator.java b/oop/11-interfaces/BasicCalculator.java
new file mode 100644
index 0000000..f087d81
--- /dev/null
+++ b/oop/11-interfaces/BasicCalculator.java
@@ -0,0 +1,15 @@
+//public class BasicCalculator implements Calculator, ScientificCalculator {
+public class BasicCalculator implements Calculator {
+
+	public int add(int a, int b) {
+		return a + b;
+	}
+
+	public int subtract(int a, int b) {
+		return a - b;
+	}
+
+	public double divide(double a, double b) {
+		return a / b;
+	}
+}
diff --git a/oop/11-interfaces/Calculator.java b/oop/11-interfaces/Calculator.java
new file mode 100644
index 0000000..aa716b0
--- /dev/null
+++ b/oop/11-interfaces/Calculator.java
@@ -0,0 +1,24 @@
+//abstract interface Calculator {
+interface Calculator {
+	public final static double PI = 3.14;
+
+	// double PI = 3.14;
+	// public static double PI = 3.14;
+	// public final double PI = 3.14;
+	// final double PI = 3.14;
+	// static double PI = 3.14;
+
+	public int add(int a, int b);
+	// int add(int a, int b);
+	// abstract int add(int a, int b);
+	// public abstract int add(int a, int b);
+
+	// static int add(int a, int b); // Not allowed
+	// int add(int a, int b); // Allowed
+	
+//	public int subtract(int a, int b);
+//	int subtract(int a, int b);
+	abstract int subtract(int a, int b);
+
+	public double divide(double a, double b);
+}
diff --git a/oop/11-interfaces/CalculatorTest.java b/oop/11-interfaces/CalculatorTest.java
new file mode 100644
index 0000000..e2340dd
--- /dev/null
+++ b/oop/11-interfaces/CalculatorTest.java
@@ -0,0 +1,9 @@
+public class CalculatorTest {
+
+	public static void main(String[] args) {
+		Calculator cal = new BasicCalculator();
+
+		System.out.println(cal.add(1, 3));
+		//....
+	}
+}
-- 
cgit v1.2.3