C# Language Equals and GetHashCode Default Equals behavior.
Example
Equals is declared in the Object class itself.
public virtual bool Equals(Object obj);
By default, Equals has the following behavior:
-
If the instance is a reference type, then
Equalswill return true only if the references are the same. -
If the instance is a value type, then
Equalswill return true only if the type and value are the same. -
stringis a special case. It behaves like a value type.
namespace ConsoleApplication
{
public class Program
{
public static void Main(string[] args)
{
//areFooClassEqual: False
Foo fooClass1 = new Foo("42");
Foo fooClass2 = new Foo("42");
bool areFooClassEqual = fooClass1.Equals(fooClass2);
Console.WriteLine("fooClass1 and fooClass2 are equal: {0}", areFooClassEqual);
//False
//areFooIntEqual: True
int fooInt1 = 42;
int fooInt2 = 42;
bool areFooIntEqual = fooInt1.Equals(fooInt2);
Console.WriteLine("fooInt1 and fooInt2 are equal: {0}", areFooIntEqual);
//areFooStringEqual: True
string fooString1 = "42";
string fooString2 = "42";
bool areFooStringEqual = fooString1.Equals(fooString2);
Console.WriteLine("fooString1 and fooString2 are equal: {0}", areFooStringEqual);
}
}
public class Foo
{
public string Bar { get; }
public Foo(string bar)
{
Bar = bar;
}
}
}
