package com.example;

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

public class MainTest {
    @Test
    @DisplayName("manipulateArray multiplies and adds correctly for positive numbers")
    void testManipulateArrayPositive() {
        int[] input = {1, 2, 3};
        int[] expected = {3, 5, 7}; // (1*2+1, 2*2+1, 3*2+1)
        int[] result = com.example.Main.manipulateArray(input, 2, 1);
        assertArrayEquals(expected, result, "Should correctly multiply and add each element");
    }

    @Test
    @DisplayName("manipulateArray does not modify original array")
    void testOriginalArrayNotModified() {
        int[] input = {4, 5, 6};
        int[] copy = input.clone();
        com.example.Main.manipulateArray(input, 3, 2);
        assertArrayEquals(copy, input, "Original array should not be modified");
    }

    @Test
    @DisplayName("manipulateArray handles empty array")
    void testEmptyArray() {
        int[] input = {};
        int[] expected = {};
        int[] result = com.example.Main.manipulateArray(input, 10, 100);
        assertArrayEquals(expected, result, "Empty input should return empty output");
    }

    @Test
    @DisplayName("manipulateArray handles negative numbers and zero")
    void testNegativeAndZero() {
        int[] input = {-1, 0, 2};
        int[] expected = {-4, -2, 2}; // (-1*2+-2, 0*2+-2, 2*2+-2)
        int[] result = com.example.Main.manipulateArray(input, 2, -2);
        assertArrayEquals(expected, result, "Should handle negative numbers and zero");
    }

    @Test
    @DisplayName("manipulateArray returns a new array instance")
    void testReturnsNewArray() {
        int[] input = {1, 2, 3};
        int[] result = com.example.Main.manipulateArray(input, 1, 1);
        assertNotSame(input, result, "Returned array should be a new instance");
    }
}

MainTest.java

A comprehensive course dedicated to understanding, designing, and applying methods in Java. Explore method fundamentals, parameter passing, overloading, recursion, and best practices through a blend of theory and hands-on coding challenges.

Explore the basics of methods in Java, including their structure, purpose, and how they enable code reuse and modularity.

Delve into parameter passing, argument types, and how methods interact with data.

Explore method overloading, recursion, and best practices for designing effective methods.

Challenge: Parameter Manipulation

Løsning

Challenge: Parameter Manipulation

Løsning