package com.example;

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

public class MainTest {
    @Test
    @DisplayName("area(int, int) returns correct area for rectangle")
    void testRectangleArea() {
        assertEquals(50, com.example.Main.area(5, 10), "Rectangle area should be width * height");
        assertEquals(0, com.example.Main.area(0, 10), "Area should be zero if width is zero");
        assertEquals(0, com.example.Main.area(10, 0), "Area should be zero if height is zero");
        assertEquals(6, com.example.Main.area(2, 3), "Area should be width * height");
    }

    @Test
    @DisplayName("area(double) returns correct area for circle")
    void testCircleArea() {
        assertEquals(Math.PI * 3.0 * 3.0, com.example.Main.area(3.0), 0.0001, "Circle area should be PI * r^2");
        assertEquals(0.0, com.example.Main.area(0.0), 0.0001, "Area should be zero if radius is zero");
    }

    @Test
    @DisplayName("area(double, double, double) returns correct area for triangle using Heron's formula")
    void testTriangleArea() {
        assertEquals(6.0, com.example.Main.area(3.0, 4.0, 5.0), 0.0001, "Triangle area should match Heron's formula for 3-4-5 triangle");
        assertEquals(0.0, com.example.Main.area(1.0, 2.0, 3.0), 0.0001, "Area should be zero when triangle is degenerate");
    }
}

MainTest.java

A hands-on introduction to Java methods, data transfer, and compiler behavior. Learn how to declare, invoke, and overload methods, work with parameters and arguments, understand pass-by-value, and implement recursion for problem-solving.

Challenge: Method Overloading

解答