預設等於行為
Equals
在 Object
類中宣告。
public virtual bool Equals(Object obj);
預設情況下,Equals
具有以下行為:
-
如果例項是引用型別,則
Equals
僅在引用相同時才返回 true。 -
如果例項是值型別,則
Equals
僅在型別和值相同時才返回 true。 -
string
是一個特例。它的行為類似於值型別。
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;
}
}
}