static void Main(string[] args)
{
/*
* Understanding class and object
* Different value and object
* Review System.Object
* Review Equals method
*/
Test t1 = new Test();
Test t2 = new Test();
// why?
bool resultEquals = object.Equals(t1, t2); // false
bool resultReferenceEquals = object.ReferenceEquals(t1, t2); // false
string writeformat = "{0}, {1}";
Console.WriteLine(writeformat, "object.Equals(t1, t2)", resultEquals);
Console.WriteLine(writeformat, "object.ReferenceEquals(t1, t2)", resultReferenceEquals);
t1.Id = 1;
t2.Id = 1;
resultEquals = object.Equals(t1.Id, t2.Id); // true
resultReferenceEquals = object.ReferenceEquals(t1.Id, t2.Id); // false, why???
Console.WriteLine(writeformat, "object.Equals(t1.Id, t2.Id)", resultEquals);
Console.WriteLine(writeformat, "object.ReferenceEquals(t1.Id, t2.Id)", resultReferenceEquals);
t1.Name = "Test";
t2.Name = "Test";
resultEquals = object.Equals(t1.Name, t2.Name); // true
resultReferenceEquals = object.ReferenceEquals(t1.Name, t2.Name); // true, why???
Console.WriteLine(writeformat, "object.Equals(t1.Name, t2.Name)", resultEquals);
Console.WriteLine(writeformat, "object.ReferenceEquals(t1.Name, t2.Name)", resultReferenceEquals);
// Diffenrent "value" and "object"
// Let's check out!
// value - struct - stack
// object - class - heap
// string type - class
#region Equals
Test2 test2_1 = new Test2()
{
Id = 1
};
Type t = test2_1.GetType(); // Name: "Test2", Namesapce: "OOP_Review_2017_1"
Test2 test2_2 = new Test2()
{
Id = 1
};
Test2 test2_3 = test2_1;
bool result = test2_1.Equals(test2_2); // true, why? override Equals method.
bool result2 = test2_1.Equals(test2_3); // true
test2_2.Id = 2;
bool result3 = test2_1.Equals(test2_2);
// 비교는 이렇게 하는게 더 쉽지 않나요?
// 반박: 그런데 이건 int 비교니까 하나 마나인듯...
if (test2_1.Id == test2_2.Id)
{
}
// Test2 type의 object가 같은가?
// 이걸 왜 비교하죠? class type도 built-in type과 동일하게 인지하고 싶으니까
if (test2_1 == test2_2)
{
}
else
{
}
#endregion
#region 원하는 주제
// 0. Delegate
// 1. Lambda
Action action = () => { };
// 2. Closure
// 3. yield???
#endregion
}
