Wednesday, September 6, 2017

Myth Buster ReferenceEquals == Equals()

Introduction


ReferenceEquals and Equals and == are pretty much does the same thing.
  • It compares the object reference to SAME instance.
  • Even if the object reference is of the same type and have same value it returns false.


using System;

namespace ConsoleApplication1
{
    
class Program
    {
        
static void Main(string[] args)
        {
      
            
var c1 = new Car(1, "Matiz");
            
var c2 = new Car(1, "Matiz");
           
            
//COMPARES OBJECT REFERENCES OF DIFFERENT INSTANCES OF SAME TYPE
            
Console.WriteLine(c1.Equals(c2));//false
            
Console.WriteLine(ReferenceEquals(c1, c2));//false
            
Console.WriteLine(c1 == c2);//false
        
            
var c3 = c2;
            
//COMPARES OBJECT REFERENCES OF SAME INSTANCES OF SAME TYPE
            
Console.WriteLine(c3.Equals(c2));//true
            
Console.WriteLine(ReferenceEquals(c3, c2));//true
            
Console.WriteLine(c3 == c2);//true

            
Console.Read();
        }

        
private class Car
        {
            
private readonly int _id;
            
private readonly string _name;

            
public Car(int id, string name)
            {
                _id = id;
                _name = name;
            }
        }
    }
}


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