IEquatable revised book, C#

Language: Layout:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
	
	class MyClass : IComparable<MyClass>, IEquatable<MyClass> 
	{

public int Val;

public MyClass(int x) 
		{ 
			Val = x; 
		}

// Implement IComparable<T>.

public int CompareTo(MyClass other) 
		{

Console.WriteLine("In MyClass.CompareTo\n");
			return Val - other.Val; // Now, no cast is needed.

}

// Implement IEquatable<T>.

public bool Equals(MyClass other) 
		{
            Console.WriteLine("In MyClass.Equals\n");

return Val == other.Val;

}

// An override of Equals(Object).

public override bool Equals(Object obj)
		{
              Console.WriteLine("In MyClass.bool.Equals\n");
			if(obj is MyClass)

return Equals((MyClass) obj);

return false;

}
		// An override of GetHashCode().

/*public override int GetHashCode() 
		{

return Val.GetHashCode();

}*/

}

class CompareDemo
	{

// Require IEquatable<T> interface.

public static bool IsIn<T>(T what, T[] obs) where T : IEquatable<T> 
		{

Console.WriteLine("In CompareDemo.bool.IsIn\n");
            Console.WriteLine(what.GetType());
			foreach(T v in obs)

if(v.Equals(what)) // Uses Equals()

return true;

return false;

}

// Require IComparable<T> interface. This method assumes

// a sorted array. It returns true if what is inside the range

// of elements passed to obs.

public static bool InRange<T>(T what, T[] obs) where T : IComparable<T> 
		{

Console.WriteLine("In CompareDemo.bool.InRange\n");
            Console.WriteLine(what.GetType());
			if(what.CompareTo(obs[0]) < 0 ||

what.CompareTo(obs[obs.Length-1]) > 0) return false;

return true;

}
	}
	public class Program
	{
		public static void Main(string[] args)
		{
			// Use IsIn() with int.

int[] nums = { 1, 2, 3, 4, 5 };

if(CompareDemo.IsIn(2, nums))

Console.WriteLine("2 is found.");

if(!CompareDemo.IsIn(99, nums))

Console.WriteLine("99 is not there.");

// Use IsIn() with MyClass.

MyClass[] mcs = { new MyClass(1), new MyClass(2),

new MyClass(3), new MyClass(4) };

if(CompareDemo.IsIn(new MyClass(3), mcs))

Console.WriteLine("MyClass(3) is found.");

if(!CompareDemo.IsIn(new MyClass(99), mcs))

Console.WriteLine("MyClass(99) is not found");

Console.WriteLine("---------------------------------------");
			// Use InRange() with int.

if(CompareDemo.InRange(2, nums))
			Console.WriteLine("2 is within the range of nums.");

if(CompareDemo.InRange(1, nums))

Console.WriteLine("1 is within the range of nums.");

if(CompareDemo.InRange(5, nums))

Console.WriteLine("5 is within the range of nums.");

if(!CompareDemo.InRange(0, nums))

Console.WriteLine("0 is NOT within the range of nums.");

if(!CompareDemo.InRange(6, nums))

Console.WriteLine("6 is NOT within the range of nums.");
            Console.WriteLine("---------------------------------------");

// Use InRange() with MyClass.

if(CompareDemo.InRange(new MyClass(2), mcs))

Console.WriteLine("MyClass(2) is within the range of mcs.");

if(CompareDemo.InRange(new MyClass(1), mcs))

Console.WriteLine("MyClass(1) is within the range of mcs.");

if(CompareDemo.InRange(new MyClass(4), mcs))

Console.WriteLine("MyClass(4) is within the range of mcs.");

if(!CompareDemo.InRange(new MyClass(0), mcs))

Console.WriteLine("MyClass(0) is NOT within the range of mcs.");

if(!CompareDemo.InRange(new MyClass(5), mcs))

Console.WriteLine("MyClass(5) is NOT within the range of mcs.");
		}
	}
}

Show compiler warnings [ + ] Show input
Compilation time: 0.25 sec, absolute running time: 0.09 sec, cpu time: 0.08 sec, average memory usage: 16 Mb, average nr of threads: 4