Quiz on Java Variables

What is the line missing in the following code ?

public class Sample {

    public void Demo ()

    {

        int a = 0;

        int b = a + 5;

        System.out.println(“B value is: ” + b);

    }

    public static void main (String args [])

    {

        Sample obj = new Sample ();

    }

}

What is the error in the program?

class demo {

public static void main ( String args [] )

{

int a;

system.out.println(“Variable value is” + a );

}

    }

What will be the output of the program?

class factorial {

public static void main ( String args [] )

{

int n = 10 , fact = 1;

for ( i = 1 , i < n , i++ )

{

fact = fact*i;

}

system.out.println(  “ Factorial of the program is “ + fact );

}

}

If the entered number is 10. How many times will the for loop be executed?

class loopexample {

public static void main {

int n , sum = 0 ;

Scanner sc = new Scanner(System.in);

system.out.println( “ Enter a number ” );

n = sc.nextint();

for( int i = n , i = 0 , i– )

{

sum = sum + i )

}

system.out.println(“ The sum of “ + n + “ natural numbers is “ + sum );

}

}

Which of the following is not a correct syntax of a variable name?

The above given program is an example of which type of Variable?

public class variableDemo { 

public void add()

{

int num = 0;

num = num + 7;

System.out.println(“The number is : ” + num);

}

public static void main( String args [] ) 

{

VariableDemo obj = new VariableDemo();

obj.add(8);

}

}

What will be the output of the program?

 public class InstanceVariableExample {

     public static void main( String args [] ) 

{

             Employee employee = new Employee();

        System.out.println(employee.companyName);

        System.out.println(employee.branches);

        System.out.println(employee.noofemp);

        employee.companyName = “DataFlair”;

        employee.branches = 10;

        employee.noofemp = 28;

     }

}

class Employee {

    public int branches;

    public String companyName;

    public int noofemp;

}

What will be the output of the program?

public class VariableExample{

    static int data = 30;

   public static void main( String args [] )

{  

      VariableExample obj = new VariableExample();

      System.out.println( VariableExample.data);

   }

}

When will a variable be destroyed?

How could a variable space be destroyed from the memory?

What happens to variable a in this program?

class example{

public static void main ( String args [] )

{

int a;

a = 10;

system.out.println(“Value of variable a is “ + a );

a = null;

}

}

How to call a garbage collector meanwhile in a program?

What will be the output of the program?

 class typecastexample {

public static void main ( String args [] )

{

int i,j,k;

i = 11;

j = 12;

k = (float) i/j;

system.out.println(k);

}

}

Why is the highlighted line used in this program?

public class demoprogram {

public static void main( String args [] ) 

{

             int x = 99;

             System.out.println(((Object)x).getClass().getSimpleName());

            }

     }

What can be done to change a variable to a constant?