Java Constructor and Methods - Quiz

Q: What is the expected output?

public class Profile {
         private Profile(int w) { // line 1
                  System.out.print(w);
         }
         public static Profile() { // line 5
                  System.out.print (10);
         }
         public static void main(String args[]) {
                  Profile obj = new Profile(50);
         }
}

A. Won't compile because of line (1), constructor can't be private
B. 10 50
C. 50
D. Won't compile because of line (5), constructor can't be static

Correct Option: D
Remarks:

Explanation: Won't compile because of line (5), constructor can't be static

Q: The following code contains one compilation error, find it?

public class Test {
	Test() {    }  // line 1
	static void Test() {  this(); } // line 2  
	public static void main(String[] args) { // line 3
		Test(); // line 4
	}
}

A. At line 1, constructor Tester must be marked public like its class
B. At line 2, constructor call
C. At line 3, compilation error, ambiguity problem, compiler can't determine whether a constructor
D. At line 4

Correct Option: B
Remarks:

Explanation: At line 2, constructor call

Q: In which area of memory, the system stores parameters and local variables whenever a method is invoked?

A. Heap
B. Storage Area
C. Stack
D. Array

Correct Option: C
Remarks:

Explanation: Stack

Q: The main method should be static for the reason

A. It can be accessed easily by the class loader.
B. It can be accessed by every method or variable without any hindrance.
C. It can be executed without creating any instance of the class.
D. None of the above

Correct Option: C
Remarks:

Explanation: It can be executed without creating any instance of the class.

Q: What is the prototype of the default constructor? public class Test { }

A. public Test(void)
B. Test( )
C. Test(void)
D. public Test( )

Correct Option: D
Remarks:

Explanation: <code>public Test( ) </code> A constructor in Java is similar to a method that is invoked when an object of the class is created. Unlike Java methods, a constructor has the same name as that of the class and does not have any return type. For example, <pre>class Test { public Test() { // constructor body } }</pre> Here, <code>Test()</code> is a constructor. It has the same name as that of the class and doesn't have a return type.

Q: What is the output for the below code ?

1. public class A{
2.       int add(int i, int j){
3.             return i+j;
4.       }
5. }
6. public class B extends A{
7.       public static void main(String argv[]){
8.             short s = 9;
9.             System.out.println(add(s,6));
10.      }
11.}

A. Compile fail due to error on line no 2
B. Compile fail due to error on line no 9
C. Compile fail due to error on line no 8
D. 15

Correct Option: B
Remarks:

Explanation: Compile fail due to error on line no 9

Q:

class MyClass{
      MyClass(){
            System.out.print("one");
      }
      public void myMethod(){
            this();
            System.out.print("two");
      }
}
 
public class TestClass{
      public static void main(String args[]){
            MyClass obj = new MyClass();
            obj.myMethod();
      }
}

which one is correct

A. two one one
B. one one two
C. one Exception
D. Compilation Error

Correct Option: D
Remarks:

Explanation: Compilation Error

Q: What is the output for the below code?

public class Test{
      public static void printValue(int i, int j, int k){
            System.out.println("int");
      }

      public static void printValue(byte...b){
            System.out.println("long");
      }

      public static void main(String... args){
            byte b = 9;
            printValue(b,b,b);
      }
}

A. long
B. int
C. Compilation fails
D. Compilation clean but throws RuntimeException

Correct Option: B
Remarks:

Explanation: int

Q: What is the output for the below code ?

class A{
      public A(){
            System.out.println("A");
      }
      public A(int i){
            this();
            System.out.println(i);
      }
}
class B extends A{
      public B(){
            System.out.println("B");
      }
      public B(int i){
            this();
            System.out.println(i+3);
      }
}
public class Test{
      public static void main (String[] args){
            new B(5);
      }
}

A. A B 8
B. A 5 B 8
C. A B 5
D. B 8 A 5

Correct Option: A
Remarks:

Explanation: A B 8

Q: Which of these is a legal definition of a method named atnyla assuming it throws IOException, and returns void. Also assume that the method does not take any arguments. Select the one correct answer.

A. void atnyla() {} throws IOException
B. void atnyla() throws IOException{}
C. void atnyla() throw IOException{}
D. void atnyla(void) throws IOException{}

Correct Option: B
Remarks:

Explanation: void examveda() throws IOException{}

Java Constructor and Methods - Quiz

What is the expected output?
public class Profile { private Profile(int w) { // line 1 System.out.print(w); } public static Profile() { // line 5 System.out.print (10); } public static void main(String args[]) { Profile obj = new Profile(50); } }

The following code contains one compilation error, find it?
public class Test { Test() { } // line 1 static void Test() { this(); } // line 2 public static void main(String[] args) { // line 3 Test(); // line 4 } }

In which area of memory, the system stores parameters and local variables whenever a method is invoked?

The main method should be static for the reason

What is the prototype of the default constructor? public class Test { }

What is the output for the below code ?
1. public class A{ 2. int add(int i, int j){ 3. return i+j; 4. } 5. } 6. public class B extends A{ 7. public static void main(String argv[]){ 8. short s = 9; 9. System.out.println(add(s,6)); 10. } 11.}

class MyClass{ MyClass(){ System.out.print("one"); } public void myMethod(){ this(); System.out.print("two"); } } public class TestClass{ public static void main(String args[]){ MyClass obj = new MyClass(); obj.myMethod(); } }
which one is correct

What is the output for the below code?
public class Test{ public static void printValue(int i, int j, int k){ System.out.println("int"); } public static void printValue(byte...b){ System.out.println("long"); } public static void main(String... args){ byte b = 9; printValue(b,b,b); } }

Which of these is a legal definition of a method named atnyla assuming it throws IOException, and returns void. Also assume that the method does not take any arguments. Select the one correct answer.

Java Constructor and Methods - Quiz

What is the expected output? public class Profile { private Profile(int w) { // line 1 System.out.print(w); } public static Profile() { // line 5 System.out.print (10); } public static void main(String args[]) { Profile obj = new Profile(50); } }

The following code contains one compilation error, find it? public class Test { Test() { } // line 1 static void Test() { this(); } // line 2 public static void main(String[] args) { // line 3 Test(); // line 4 } }

In which area of memory, the system stores parameters and local variables whenever a method is invoked?

The main method should be static for the reason

What is the prototype of the default constructor? public class Test { }

What is the output for the below code ? 1. public class A{ 2. int add(int i, int j){ 3. return i+j; 4. } 5. } 6. public class B extends A{ 7. public static void main(String argv[]){ 8. short s = 9; 9. System.out.println(add(s,6)); 10. } 11.}

class MyClass{ MyClass(){ System.out.print("one"); } public void myMethod(){ this(); System.out.print("two"); } } public class TestClass{ public static void main(String args[]){ MyClass obj = new MyClass(); obj.myMethod(); } } which one is correct

What is the output for the below code? public class Test{ public static void printValue(int i, int j, int k){ System.out.println("int"); } public static void printValue(byte...b){ System.out.println("long"); } public static void main(String... args){ byte b = 9; printValue(b,b,b); } }

Which of these is a legal definition of a method named atnyla assuming it throws IOException, and returns void. Also assume that the method does not take any arguments. Select the one correct answer.

What is the expected output?
public class Profile { private Profile(int w) { // line 1 System.out.print(w); } public static Profile() { // line 5 System.out.print (10); } public static void main(String args[]) { Profile obj = new Profile(50); } }

The following code contains one compilation error, find it?
public class Test { Test() { } // line 1 static void Test() { this(); } // line 2 public static void main(String[] args) { // line 3 Test(); // line 4 } }

What is the output for the below code ?
1. public class A{ 2. int add(int i, int j){ 3. return i+j; 4. } 5. } 6. public class B extends A{ 7. public static void main(String argv[]){ 8. short s = 9; 9. System.out.println(add(s,6)); 10. } 11.}

class MyClass{ MyClass(){ System.out.print("one"); } public void myMethod(){ this(); System.out.print("two"); } } public class TestClass{ public static void main(String args[]){ MyClass obj = new MyClass(); obj.myMethod(); } }
which one is correct

What is the output for the below code?
public class Test{ public static void printValue(int i, int j, int k){ System.out.println("int"); } public static void printValue(byte...b){ System.out.println("long"); } public static void main(String... args){ byte b = 9; printValue(b,b,b); } }