Two .NET objects that are equal don't say they are

Question

I have the following code:

object val1 = 1;
object val2 = 1;

bool result1 = (val1 == val2);//Equals false
bool result2 = val1.Equals(val2); //Equals true
         


        

Answer 1

The CIL for your code boxes the two integers and compares the two objects that result from the boxing (==). This comparison is by reference.

  .locals init ([0] object val1,
           [1] object val2,
           [2] bool result1,
           [3] bool result2)
  IL_0000:  nop
  IL_0001:  ldc.i4.1
  IL_0002:  box        [mscorlib]System.Int32
  IL_0007:  stloc.0
  IL_0008:  ldc.i4.1
  IL_0009:  box        [mscorlib]System.Int32
  IL_000e:  stloc.1
  IL_000f:  ldloc.0
  IL_0010:  ldloc.1
  IL_0011:  ceq
  IL_0013:  stloc.2
  IL_0014:  ldloc.0
  IL_0015:  ldloc.1
  IL_0016:  callvirt   instance bool [mscorlib]System.Object::Equals(object)
  IL_001b:  stloc.3

For the .Equals it calls Object.Equals, which calls Int32.Equals (virtual method call on Object):

public override bool Equals(object obj)
{
    return ((obj is int) && (this == ((int) obj)));
}

This casts to int and compares the values as integers, a value type comparison.