
using Xunit;
using Xunit;
using System;
using System.IO;

namespace ConsoleApp {
    public class ProgramTests {
        [Fact(DisplayName = "PrintArrayReverse prints all elements in reverse order, one per line")] 
        public void PrintArrayReverse_PrintsReverseOrder() {
            var arr = new string[] { "Apple", "Banana", "Cherry", "Date" };
            var sw = new StringWriter();
            Console.SetOut(sw);

            Program.PrintArrayReverse(arr);
            string output = sw.ToString().Trim();
            var lines = output.Split(new[] {'\\n', '\\r'}, StringSplitOptions.RemoveEmptyEntries);
            Assert.Equal("Date", lines[0]);
            Assert.Equal("Cherry", lines[1]);
            Assert.Equal("Banana", lines[2]);
            Assert.Equal("Apple", lines[3]);
            Assert.Equal(4, lines.Length);
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }

        [Fact(DisplayName = "PrintArrayReverse handles single element array")] 
        public void PrintArrayReverse_SingleElement() {
            var arr = new string[] { "One" };
            var sw = new StringWriter();
            Console.SetOut(sw);

            Program.PrintArrayReverse(arr);
            string output = sw.ToString().Trim();
            Assert.Equal("One", output);
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }

        [Fact(DisplayName = "PrintArrayReverse handles empty array (prints nothing)")] 
        public void PrintArrayReverse_EmptyArray() {
            var arr = new string[0];
            var sw = new StringWriter();
            Console.SetOut(sw);

            Program.PrintArrayReverse(arr);
            string output = sw.ToString();
            Assert.True(string.IsNullOrWhiteSpace(output), "Expected no output for empty array");
            Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = true });
        }
    }
}

ProgramTests.cs

Master the essentials and advanced techniques of working with arrays in C#. This course guides you from the basics of declaring and initializing arrays, through practical manipulation, searching, and advanced operations like sorting and matrix calculations. Each section blends engaging theory with real-world themed challenges to ensure a hands-on, beginner-friendly learning experience.

Challenge: Reverse Print

Solution