CODEWITHSUNDEEP
c#
user1149291
user1149291

Reputation: 19

Calling method or functions in c#

I'm new in C#, could you please tell me that what's my problem here. I know it's very simple for you but it's not for me :(

My short code :

class A 
{ 
    private int B; 
    public void b(){ }
    public void c(){ B = b( );}
    static void Main ( string [ ] args ) 
    {
        c(); 
    }
}

My Error is :

An object reference is required for the non-static field, method, or property 'GMBL.Program.Start()'

How can I fix it?

Upvotes: 1

Views: 143

Answers (9)

Pritam Karmakar
Pritam Karmakar

Reputation: 2801

Static methods are not associated with a class instance. In your case method C() is a non-static method i.e. it is associated with a class instance and to access C() from a static method you have to first create an object of your class A. Then call C() from that object.

So inside Main() method use below 2 lines

A obj = new A();
obj.C();

Upvotes: 0

Alex
Alex

Reputation: 35409

change public void c()

to public static void c()

or

Create a new instance of class A and call the instance member c();

static void Main ( string [ ] args ) 
{
    var foo = new A();
    foo.c();
}

As @SLaks pointed out you cannot call instance members of a type from a static member of the same type, or some other type, without a reference of said type.

Upvotes: 2

Ravindra Gullapalli
Ravindra Gullapalli

Reputation: 9158

Two issues are there in your code.

Issue#1 : You can not use non-static members in static methods.

To use c() in your main method, either you have to change c() to a static method like 

public static void c(){....}

OR declare an object for your class A and then call c() with that object instance like

A objA = new A();
objA.c();

Issue#2 : The statement 

B = b( );

is wrong because the method b() is not returning any value.

First change 

private B;

to 

private int B; // Or some thing like this

and then

public void b(){ }

to 

public int b(){}

Hope this helps.

Upvotes: 0

Chen Kinnrot
Chen Kinnrot

Reputation: 21015

first, you can't write private B, you must give be a type. second, b does not return any value, so you can't assign it to B

Upvotes: 0

Gustavo F
Gustavo F

Reputation: 2206

If you don't want to instantiate a new class, simple make the c static, example:

public static void c()

Upvotes: 0

kprobst
kprobst

Reputation: 16651

Move the Main function out to another static class, and within it create an instance of A, and call the method:

class A 
{ 
    private B; 
    public void b(){ }
    public void c(){ B = b( );}
} 

class Program 
{
    public static void Main ( string [ ] args ) 
    {
        A a = new A();
        a.c(); 
    }
}

The app's entry point should generally live in its own independent class.

Upvotes: 0

RG-3
RG-3

Reputation: 6188

You have to create an object for your class A.

ClassA a1 = new classA();
a1.c();

Upvotes: 0

D Stanley
D Stanley

Reputation: 152556

You are referencing a non-static function c() from the static function Main(). Either make c() static or create an instance of A and call c() on it:

A a = new A();
a.c();
// do something with a

Upvotes: 0

SLaks
SLaks

Reputation: 887453

Main is a static method – it is not associated with an instance of your class.

c is an instance method – it operates on an instance of your class.
You can only call c on an instance.

Upvotes: 6

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