tobper/ObjectCompare

Recursive object comparer

ObjectCompare

Recursive object comparer for .Net.

Usage

ObjectComparer.Equals(1, 2);

var x = new { Name = "John" };
var y = new { Name = "Jane" };

ObjectComparer.Equals(x, y);

var x = new[] { 1, 2 };
var y = new[] { 2, 3 };

ObjectComparer.Equals(x, y);

Order of execution

Each object pair will be compared according to the following order of execution.

1. Value type check

   Objects are equal if the type is a value type and an equal check (==) returns true;

2. Null value check

   Objects are equal if both references are null.
   Objects are not equal if one of the references is null.

3. ReferenceEquals check

   Objects are equal if Object.ReferenceEquals(x1, x2) returns true.

4. Visited objects check

   Ensures that the object pair has not already been evaluated to prevent infinite loops which will lead to stack overflows.

   class X
   {
       public Y Y { get; set; }
   }
   
   class Y
   {
       public X X { get; set; }
   }

   The following code will work because the combination of x1 and x2 has already been evaluated when x.Y.X is reached.

   var x1 = new X { Y = new Y() };
   var x2 = new X { Y = new Y() };
   x1.Y.X = x1;
   x2.Y.X = x2;
   
   ObjectComparer.Equals(x1, x2);

   More complicated relationships will work the same way; x1.Y.X is the same object as x2.X.Y.X.Y.X.

   var x1 = new X { Y = new Y() };
   var x2 = new X { Y = new Y { X = new X { Y = new Y() } } };
   x1.Y.X = x1;
   x2.Y.X.Y.X = x2;
   
   ObjectComparer.Equals(x1, x2);

5. IEquatable<T> check

   Objects are equal if the type implements IEquatable<T> and x1.Equals(x2) returns true.

6. ICollection<T> check

   Objects are not equal if the type implements ICollection<T> and x1.Count != x2.Count.

7. IEnumerable<T> check

   Objects are equal if the type implements IEbumerable<T>, all the items are equal and the enumerables are of the same length.

8. Member check

   Compares public properties, protected properties and private fields according to specified settings.
   Each member pair will be compared from the top of this list.

Settings

• PrivateFields

  Specify true if private fields should be included in the member check.
  Default values is false.

• ProtectedProperties

  Specify true if protected properties should be included in the member check.
  Default values is false.

• PublicProperties

  Specify true if public properties should be included in the member check.
  Default values is true.

• UseEquatable

  Specify true if IEquatable should be used if types implements it.
  Default values is true.

Contact

Feel free to send a mail to objectcompare@ohnoes.eu with questions or comments.