polymorphism on abstract class

venus najad

hello... i have an issue and need help... i will calculate two circuits with two resistors, parallel or serie... for this i have created an abstract class KretsDel, which has two protected fields(resistors), and abstract property, Total and a constructor.

further i have created two classes Parallel and Serie, which contains the propertyTotal which returns the result of resistors connections.

further i have created a class Krets with a field List and two methoder for calculation of serie or parallel coupling for each element in List... but i get errors...

the following is my codes:

class Program
{
static void Main(string[] args)
{
Krets k = new Krets();
}
}
abstract class KretsDel
{
protected float R1, R2;
public abstract float Total
{
get;
set;
}
public KretsDel(int r1,int r2)
{
this.R1 = r1;
this.R2 = r2;
}
}
class Parallel : KretsDel
{
override public float Total
{
set
{
this.R1 = value;
this.R2 = value;
}
get { return parallel(this.R1, this.R2); }
}
public float parallel(float r1, float r2)
{
float R = r1 *r2 / (r1 + r2);
return R;
}
}
class Serie : KretsDel
{
override public float Total
{
set
{
this.R1 = value;
this.R2 = value;
}
get { return serie(this.R1, this.R2); }
}
public float serie(float r1, float r2)
{
float R =r1 + r2;
return R;
}
}
public class Krets
{
static Parallel parallel = new Parallel();
static Serie serie = new Serie();
List lkd = new List() { parallel, serie };
foreach(var k in lkd)
k.Total;
public float ser(float r1, float r2)
{
float R = r1 + r2;
return R;
}
public float para(float r1, float r2)
{
float R = r1 * r2 / (r1 + r2);
return R;
}
}

appreciate any help... kind regards

5 Replies

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venus najad7y ago
thanks... i have read about abstract, but i couldnt solve it... it works and i close this question...thansk and kind regards
0
Mario Scheeren7y ago
I used your code and the only thing I changed is
Console.WriteLine("please enter two resistors");
var r = Console.ReadLine().Split(' ');
Parallel parallel = new Parallel(float.Parse(r[0]), float.Parse(r[1]));
Serie serie = new Serie(float.Parse(r[0]), float.Parse(r[1]));
List lkd = new List() { parallel, serie };


foreach (var k in lkd)
{
    Console.WriteLine($"{k.GetType()}.Total = { k.Total }");
}
within the foreach ... since "Total" is a Property you simply cannot use it like a method.
var result = k.Total; // works
Console.WriteLine(k.Total); // works
k.Total; // Fails

Sorry, but like I said => you have to learn the basics first.
- What is a property,
- Difference between property and method,

- What are the modifiers for, what do they do, why use / when to use

Btw, Lambda is your friend - so use it!

Cheers, no offense, Mario
0
venus najad7y ago
hello again: i have changed my codes as follows:
class Program
{
static void Main(string[] args)
{
Console.WriteLine("please enter two resistors");
var r = Console.ReadLine().Split(' ');
Parallel parallel = new Parallel(float.Parse(r[0]), float.Parse(r[1]));
Serie serie = new Serie(float.Parse(r[0]), float.Parse(r[1]));
List lkd = new List() { parallel, serie };
foreach (var k in lkd)
k.Total;
}
}
abstract class KretsDel
{
protected float R1, R2;
public abstract float Total
{
get;
set;
}
public KretsDel(float r1,float r2)
{
this.R1 = r1;
this.R2 = r2;
}
}
class Parallel : KretsDel
{
override public float Total
{
set { R1 = R2 = value; }
get { return R1 * R2 / (R1 + R2); }
}
public Parallel(float r1, float r2) : base(r1, r2)
{
}
}
class Serie : KretsDel
{
override public float Total
{
set { R1 = R2 = value; }
get { return R1 + R2; }
}
public Serie(float r1, float r2) : base(r1, r2)
{
}
}
but in main method, after foreach, when i call k.Total i get error... it doesnt take as Parallel.Total of Serie.Total, only KretsDel.Total... even k is a member of the list, parallel and serie...

can you solve it? thanks and kind regards
0
venus najad7y ago
thanks mario for your respond
in my codes, when i define class Parallel and Serie, which inhereit from KretsDel, i get error on constructor Parallel() and Serie():
"there is no argument given that correspond to the required formal parameter r1 of KretsDe.KretsDel(float, float)", why is that?
these constructors are needed in my Krets class, when i make objects of class Parallel and Serie to indicate in my List...
I need Krets class, because i cannot make an object of the abstract class KretsDel, the error is:
"cannot create an instance of the abstract class or interface KretsDel"!!!!?
besides i get error on my foreach loop: "invalide token foreach in class, struct and interface member declaration"... why is that?
thanks if yo answer me...kind regards
0
Mario Scheeren7y ago
Your Krets class makes absolutely no sense. You MUST NOT write code in body of class.
Your modifiers "static" make no sense.

I suggest you learning the basics first before trying to move on to polymorphosm or anything else.
abstract class KretsDel
{
    protected float R1, R2;
    public abstract float Total { get; set; }

    public KretsDel(float r1, float r2)
    {
        R1 = r1;
        R2 = r2;
    }
}

class Parallel : KretsDel
{
    override public float Total
    {
        set => R1 = R2 = value;
        get => R1 * R2 / (R1 + R2);
    }
    public Parallel(float r1, float r2) : base(r1, r2)
    {
    }
}
class Serie : KretsDel
{
    override public float Total
    {
        set => R1 = R2 = value;
        get => R1 + R2
    }

    public Serie(float r1, float r2) : base(r1, r2)
    {
    }
}
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