
using Xunit;
namespace ConsoleApp {
    public class ProgramTests {
        [Fact(DisplayName = "SumMatrix returns correct sum for 3x3 positive integer matrix")] 
        public void SumMatrix_ReturnsSum_PositiveMatrix() {
            int[,] matrix = {
                {1, 2, 3},
                {4, 5, 6},
                {7, 8, 9}
            };
            Assert.Equal(45, Program.SumMatrix(matrix));
        }

        [Fact(DisplayName = "SumMatrix returns 0 for matrix with all zeros")]
        public void SumMatrix_ReturnsZero_AllZeros() {
            int[,] matrix = {
                {0, 0},
                {0, 0}
            };
            Assert.Equal(0, Program.SumMatrix(matrix));
        }

        [Fact(DisplayName = "SumMatrix correctly sums negative and positive numbers")]
        public void SumMatrix_NegativePositiveNumbers() {
            int[,] matrix = {
                {-1, 2},
                {3, -4}
            };
            Assert.Equal(0, Program.SumMatrix(matrix));
        }

        [Fact(DisplayName = "SumMatrix works for non-square matrices")]
        public void SumMatrix_NonSquareMatrix() {
            int[,] matrix = {
                {1, 2, 3},
                {4, 5, 6}
            };
            Assert.Equal(21, Program.SumMatrix(matrix));
        }
    }
}

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: Matrix Sum

Solution