Classes and Objects in C Sharp MCQ question and answer with solution | C# Program MCQs

interface calc
{
    void cal(int i);
}
public  class maths :calc 
{
    public int x;
    public void cal(int i) 
    {
        x = i * i;            
    }
}
class Program
{
    public static void Main(string[] args)
    {            
        display arr = new display();
        arr.x = 0;      
        arr.cal(2);
        Console.WriteLine(arr.x);
        Console.ReadLine();
    }
}

enum color:int
{
    red,
    green,
    blue = 5,
    cyan,
    pink = 10,
    brown
}
console.writeline((int)color.green);
console.writeline((int)color.brown);

class maths
{
    int i;
    public  maths(int ii)
    {
        ii = -25;
        int g;
        g = ii > 0 ? ii : ii * -1;
        Console.WriteLine(g);
    }
}
class maths1 :maths
{
    public  maths1(int ll) :base(ll)
    {
        ll = -1000;
        Console.WriteLine((ll > 0 ? ll : ll * -1));
    }
}
class Program
{
    static void Main(string[] args)
    {
        maths1 p = new maths1(6);
        Console.ReadLine();
    }
}

class maths
{
    public static void fun1()
    {
        Console.WriteLine("method 1 :");
    }
    public void fun2()
    {
        fun1();
        Console.WriteLine("method 2 :");
    }
    public void fun2(int k)
    {
        Console.WriteLine(k);
        fun2();
    }
}    
class Program
{
    static void Main(string[] args)
    {
        maths obj = new maths();
        maths.fun1();
        obj.fun2(20);
        Console.ReadLine();
    }
}

static void Main(string[] args)
{
    int a = 10 , b = 20;
    Console.WriteLine("Result before swap is: "+ a +" "+b);
    swap(ref a, ref b);
    Console.ReadLine();
}
static void swap(ref int i, ref int j)
{
    int t;
    t = i;
    i = j;
    j = t;
    Console.WriteLine("Result after swap is:"+ i +" "+j);
}