
using Xunit;
namespace ConsoleApp {
    public class ProgramTests {
        [Fact(DisplayName = "Returns correct count for multiple occurrences")] 
        public void Returns_CorrectCount_MultipleOccurrences() {
            int[] arr = { 4, 2, 7, 4, 9, 4, 3 };
            Assert.Equal(3, Program.CountOccurrences(arr, 4));
        }

        [Fact(DisplayName = "Returns zero when value not in array")] 
        public void Returns_Zero_WhenValueNotInArray() {
            int[] arr = { 1, 2, 3, 5 };
            Assert.Equal(0, Program.CountOccurrences(arr, 4));
        }

        [Fact(DisplayName = "Returns correct count for single occurrence")] 
        public void Returns_CorrectCount_SingleOccurrence() {
            int[] arr = { 1, 2, 4, 5 };
            Assert.Equal(1, Program.CountOccurrences(arr, 4));
        }

        [Fact(DisplayName = "Works for empty array")] 
        public void Works_ForEmptyArray() {
            int[] arr = { };
            Assert.Equal(0, Program.CountOccurrences(arr, 4));
        }
    }
}

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: Count Occurrences

Solution