C# week6_3

03/03/2010

 

int i;

int i1, i2;

i1 = 5;

i2 = 7;

i1 = i2;

i1	5
i2	7

i1 is assigned i2 stored value.

Reference = Parse

 

class A { }

A a1 = new A();

A a2 = new A();

a1 = a2; (It will work.)

a1 is assigned address of a2Memory Location.

a1 memory location is not used by any object.

 

Garbage Collector: used free on memory location

If you want Garbage Collector to collect memory, you should write on your program.

 

class A { }

class B { }

A a1 = new A;

B b1 = new B;

a1 = b1; (error)

It means you assign different data type.

 

class A { }

A a1, a2;

a1 = new A();

a2 = new A();

a1 = a2;

Once you assign a1 to a2, you can't back.

 

class A { }

class B { }

A a1,a2,a3;

a1 = new A();

a1 = null; (remove memory location)

 

Parents valuable can refer child object.

class B

class A : B

Parent B b = new B();

child A a = new A();

b = a; (OK)

a = b; (error)

 

Polymorphism: more than one behaviour

class A

{

public virtual void abc()

{

}

}

class B : A

{

override public void abc()

{

}

}

A a = new B(); (B is initialized)

a.abc();