Interfaces
- AutoCloseable and Flushable are part of which package?
-
View Hint View Answer Discuss in Forum
NA
Correct Option: C
Autocloseable is a part of java.lang; Flushable is a part of java.io.
- Can “abstract” keyword be used with constructor, Initialization Block, Instance Initialization and Static Initialization Block.
-
View Hint View Answer Discuss in Forum
NA
Correct Option: B
No, Constructor, Static Initialization Block, Instance Initialization Block and variables cannot be abstract.
- What is the output of this program?
interface calculation
{
void calculate(int Num);
}
class display implements calculation
{
int p;
public void calculate(int Num)
{
p = Num * Num;
}
}
public class interfaces_Example
{
public static void main(String args[])
{
display object = new display();
object.p = 0;
object.calculate(4);
System.out.print(object.p);
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: C
16
- What is the output of this program?
interface Calculation
{
void calculate(int item);
}
class display0 implements Calculation
{
int p;
public void calculate(int num)
{
p = num * num;
}
}
class display1 implements Calculation
{
int p;
public void calculate(int num)
{
p = num / num;
}
}
public class interfaces_Example
{
public static void main(String args[])
{
display0 object0 = new display0();
display1 object1 = new display1();
object0.p = 0;
object1.p = 0;
object0.calculate(5);
object1.calculate(5);
System.out.print(object0.p + " " + object1.p);
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: A
class display0 implements the interface calculate by doubling the value of num, where as class display1 implements the interface by dividing num by num, therefore variable p of class display0 stores 25 and variable p of class display1 stores 1.
- What is the output of this program?
interface Calculation
{
int var = 0;
void calculate(int num);
}
class display implements Calculation
{
int p;
public void calculate(int num)
{
if (num<2)
{
p = var;
}
else
{
p = num * num;
}
}
}
public class interfaces_Example
{
public static void main(String args[])
{
display[] array = new display[4];
for(int k=0; k<4; k++)
array[k] = new display();
array[0].calculate(0);
array[1].calculate(2);
array[2].calculate(4);
System.out.print(array[0].p+" " + array[1].p + " " + array[2].p);
}
}
-
View Hint View Answer Discuss in Forum
NA
Correct Option: A
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