Java Declaration and Access Control(1st) : Question 1 of 25

What will be the output?

public class Test{
      public static void main(String[] args){
            String value = "abc";
            changeValue(value);
            System.out.println(value);
      }

      public static void changeValue(String a){
            a = "xyz";
      }
}

What will be the output?

public class Test{
      public static void main(String[] args){
            String value = "abc";
            changeValue(value);
            System.out.println(value);
      }

      public static void changeValue(String a){
            a = "xyz";
      }
}

1 Mark(s)

Compilation clean but no output
xyz
None of these
Compilation fails
abc

What is the result of compiling and running the following code?

public class Tester{
	static int x = 4;
	public Tester(){
		System.out.print(this.x); // line 1
		Tester();
	}
	public static void Tester(){ // line 2
		System.out.print(this.x); // line 3
	}
	public static void main(String... args){ // line 4
		new Tester();
	}
}

What is the result of compiling and running the following code?

public class Tester{
	static int x = 4;
	public Tester(){
		System.out.print(this.x); // line 1
		Tester();
	}
	public static void Tester(){ // line 2
		System.out.print(this.x); // line 3
	}
	public static void main(String... args){ // line 4
		new Tester();
	}
}

1 Mark(s)

Compile error at line 3 (static methods can't invoke this)
Compile error at line 4 (invalid argument type for method main )
Compile error at line 2 (constructors can't be static)
44
Compile error at line 1 (static x must be only accessed inside static methods)

Choose all the lines which if inserted independently instead of "//insert code here" will allow the following code to compile:

public class Test{   
        public static void main(String args[]){
	        add(); 
		add(1);
		add(1, 2); 
	}

	// insert code here
}

Choose all the lines which if inserted independently instead of "//insert code here" will allow the following code to compile:

public class Test{   
        public static void main(String args[]){
	        add(); 
		add(1);
		add(1, 2); 
	}

	// insert code here
}

1 Mark(s)

static void add(int...args){}
static void add(int args...){}
static void add(int[]... args){}
void add(Integer... args){}
static void add(int... args, int y){}

Consider the following two classes declared and defined in two different packages, what can be added in class B to form what considered a correct access to class A from main() method of class B?

package subPackage;
public class A { }


package anotherPackage;
// line 1
	public class B{
		public static void main(String[] args){
		// line 2
	}
}

1. At line1 add noting; At line2 add: new A();
2. At line 1 add: import package.*; at line 2 add : new subPackage.A();
3. At line 1 add: import subPackage.*; at line 2 add : new A();
4. At line 1 add: import subPackage.A; at line 2 add : new A();

Consider the following two classes declared and defined in two different packages, what can be added in class B to form what considered a correct access to class A from main() method of class B?

package subPackage;
public class A { }


package anotherPackage;
// line 1
	public class B{
		public static void main(String[] args){
		// line 2
	}
}

1 Mark(s)

1 and 3
2 and 4
1 and 2
3 and 4

What can directly access and change the value of the variable qusNo?

package com.mypackage;

public class Test{
    private int qusNo = 100;
}

What can directly access and change the value of the variable qusNo?

package com.mypackage;

public class Test{
    private int qusNo = 100;
}

1 Mark(s)

Any class in com.mypackage package.
None of these
Only the Test class.
Any class.
Any class that extends Test.

Determine output:

public class InitDemo{
	static int i = demo();
	static{
                System.out.print(i);
        }
	InitDemo(){
		System.out.print("hello1");
	}
	public static void main(String... args){
                System.out.print("Hello2");
	}
 	static int demo(){
        	System.out.print("InsideDemo");
		return 10;
	}
}

Determine output:

public class InitDemo{
	static int i = demo();
	static{
                System.out.print(i);
        }
	InitDemo(){
		System.out.print("hello1");
	}
	public static void main(String... args){
                System.out.print("Hello2");
	}
 	static int demo(){
        	System.out.print("InsideDemo");
		return 10;
	}
}

1 Mark(s)

Hello2 InsideDemo 10
InsideDemo 10 Hello2 hello1
InsideDemo 10 Hello2
IllegalArgumentException is thrown at runtime.
Compilation error.

Suppose a class has public visibility. In this class we define a protected method. Which of the following statements is correct?

1 Mark(s)

This method is accessible from within the class itself and from within all classes defined in the same package as the class itself.
From within protected methods you do not have access to public methods.
In a class, you cannot declare methods with a lower visibility than the visibility of the class in which it is defined.
This method is only accessible from inside the class itself and from inside all subclasses.

What will be the output?

public class Test{
	static{
		int a = 5;
	}

	public static void main(String args[]){
		new Test().call();
	}

	void call(){
		this.a++;
		System.out.print(this.a);
	}
}

What will be the output?

public class Test{
	static{
		int a = 5;
	}

	public static void main(String args[]){
		new Test().call();
	}

	void call(){
		this.a++;
		System.out.print(this.a);
	}
}

1 Mark(s)

6
5
0
Runtime Exception
Compile with error

A method within a class is only accessible by classes that are defined within the same package as the class of the method. Which one of the following is used to enforce such restriction?

1 Mark(s)

Do not declare the method with any accessibility modifiers.
Declare the method with the keyword public and private.
Declare the method with the keyword public.
Declare the method with the keyword private.
Declare the method with the keyword protected.

What will be the output for the below code?

public class Test{
      static{
            int a = 5; 
      }

      public static void main(String[] args){
            System.out.println(a);
      }
}

What will be the output for the below code?

public class Test{
      static{
            int a = 5; 
      }

      public static void main(String[] args){
            System.out.println(a);
      }
}

1 Mark(s)

0
Compile with error
Runtime Exception
5
None of these

What will be the output for the below code?

static public class Test{
      public static void main(String[] args){
            char c = 'a';

            switch(c){
                  case 65 : System.out.println("one");break;
		  case 'a': System.out.println("two");break;
		  case 3  : System.out.println("three");
            }	
      }
}

What will be the output for the below code?

static public class Test{
      public static void main(String[] args){
            char c = 'a';

            switch(c){
                  case 65 : System.out.println("one");break;
		  case 'a': System.out.println("two");break;
		  case 3  : System.out.println("three");
            }	
      }
}

1 Mark(s)

Compile error - char can't be permitted in switch statement.
Compile error - Illegal modifier for the class Test; only public, abstract & final are permitted.
one
two
None of these

What is the result of compiling and running the following code?

public class Tester{
	static int x = 4;
	int y = 9;  	
	public Tester(){
		System.out.print(this.x); // line 1
		printVariables();
	}
	public static void printVariables(){
		System.out.print(x); // line 2
		System.out.print(y); // line 3
	}
	public static void main(String... args) { // line 4
		new Tester();
	}
}

What is the result of compiling and running the following code?

public class Tester{
	static int x = 4;
	int y = 9;  	
	public Tester(){
		System.out.print(this.x); // line 1
		printVariables();
	}
	public static void printVariables(){
		System.out.print(x); // line 2
		System.out.print(y); // line 3
	}
	public static void main(String... args) { // line 4
		new Tester();
	}
}

1 Mark(s)

Compile error at line 1 (static x must be only accessed inside static methods)
Compile error at line 3 (static methods can't make reference to non-static variables)
49
Compile error at line 4 (invalid argument type for method main)
Compile error at line 2 (must access x by writing Tester.x)

Determine output:

class A{
	{
		System.out.print("b1 ");
	}
	public A(){
		System.out.print("b2 ");
	}
}

class B extends A{
	static{
		System.out.print("r1 ");
	}
	public B(){
		System.out.print("r2 ");
	}
	{
		System.out.print("r3 ");
	}
	static{
		System.out.print("r4 ");
	}
}

public class Test extends B{
	public static void main(String[] args){
		System.out.print("pre ");
		new Test();
		System.out.println("post ");
	}
}

Determine output:

class A{
	{
		System.out.print("b1 ");
	}
	public A(){
		System.out.print("b2 ");
	}
}

class B extends A{
	static{
		System.out.print("r1 ");
	}
	public B(){
		System.out.print("r2 ");
	}
	{
		System.out.print("r3 ");
	}
	static{
		System.out.print("r4 ");
	}
}

public class Test extends B{
	public static void main(String[] args){
		System.out.print("pre ");
		new Test();
		System.out.println("post ");
	}
}

1 Mark(s)

r1 r4 pre b1 b2 r3 r2 post
r1 r4 pre b1 b2 post
pre r1 r4 b1 b2 r2 r3 post
r1 r4 pre b1 b2 post r3 r2
Compilation fail

Determine Output:

class MyClass{
      static final int a = 20;

      static final void call(){
            System.out.println("two");
      }
	
      static{
            System.out.println("one");
      }
}

public class Test{
      public static void main(String args[]){
            System.out.println(MyClass.a);
      }
}

Determine Output:

class MyClass{
      static final int a = 20;

      static final void call(){
            System.out.println("two");
      }
	
      static{
            System.out.println("one");
      }
}

public class Test{
      public static void main(String args[]){
            System.out.println(MyClass.a);
      }
}

1 Mark(s)

one two 20
one two
20
one
one 20

What is the output for the below code ?

public class A{
      static{
            System.out.println("static");
      }

      {
            System.out.println("block");
      }

      public A(){
            System.out.println("A");
      }

      public static void main(String[] args){
            A a = new A();
      }
}

What is the output for the below code ?

public class A{
      static{
            System.out.println("static");
      }

      {
            System.out.println("block");
      }

      public A(){
            System.out.println("A");
      }

      public static void main(String[] args){
            A a = new A();
      }
}

1 Mark(s)

static A
static block A
None of these
A
A block static

What will be the output after the following program is compiled and executed?

public class Test{
      public static void main(String args[]){
            int x = 10;
	    x = myMethod(x--);
	    System.out.print(x);
      }

      static int myMethod(final int x){
            return x--;
      }
}

What will be the output after the following program is compiled and executed?

public class Test{
      public static void main(String args[]){
            int x = 10;
	    x = myMethod(x--);
	    System.out.print(x);
      }

      static int myMethod(final int x){
            return x--;
      }
}

1 Mark(s)

The program will lead to compilation error.
The program will lead to runtime error.
The will compile successfully and display 9 as output.
None of these
The program will compile successfully and display 10 as output.

You have the following code in a file called Test.java

class Base{
      public static void main(String[] args){
            System.out.println("Hello");
      }
}
public class Test extends Base{}

What will happen if you try to compile and run this?

You have the following code in a file called Test.java

class Base{
      public static void main(String[] args){
            System.out.println("Hello");
      }
}
public class Test extends Base{}

What will happen if you try to compile and run this?

1 Mark(s)

Runtime error
Compiles and runs printing
Compiles and runs with no output.
It will fail to compile.

What is the result of compiling and running the following code?

class Base{
        private Base(){
                System.out.print("Base");
        }
}
public class test extends Base{
        public test(){
                System.out.print("Derived");
        }
        public static void main(String[] args){
                new test();
        }
}

What is the result of compiling and running the following code?

class Base{
        private Base(){
                System.out.print("Base");
        }
}
public class test extends Base{
        public test(){
                System.out.print("Derived");
        }
        public static void main(String[] args){
                new test();
        }
}

1 Mark(s)

Derived
BaseDerived
Compilation Error
Exception is thrown at runtime

Name the keyword that makes a variable belong to a class, rather than being defined for each instance of the class.

1 Mark(s)

abstract
volatile
native
final
static

Which statements are most accurate regarding the following classes?

class A{
        private int i;
        protected int j;
}

class B extends A{
        private int k;
        protected int m;
}

Which statements are most accurate regarding the following classes?

class A{
        private int i;
        protected int j;
}

class B extends A{
        private int k;
        protected int m;
}

1 Mark(s)

An object of B contains data fields i, j, k, m.
An object of B contains data fields j, m.
An object of B contains data fields k, m.
An object of B contains data fields j, k, m.

What will be the output after compiling and running following program code?

public class Test{
      static int a;
      public static void main(String[] args){
            System.out.println("one");
            call(1);
      }

      static void call(int a){
            this.a=10;
            System.out.println("two "+a);
      }
}

What will be the output after compiling and running following program code?

public class Test{
      static int a;
      public static void main(String[] args){
            System.out.println("one");
            call(1);
      }

      static void call(int a){
            this.a=10;
            System.out.println("two "+a);
      }
}

1 Mark(s)

Compile time error.
one two 0
None of these
one two 1
one two 10

Choose the correct statement

public class Circle{
      private double radius;  
      public Circle(double radius){
            radius = radius;
      }
}

Choose the correct statement

public class Circle{
      private double radius;  
      public Circle(double radius){
            radius = radius;
      }
}

1 Mark(s)

The program does not compile because Circle does not have a default constructor.
The program will compile, but we cannot create an object of Circle with a specified radius. The object will always have radius 0.
The program has a compilation error because it does not have a main method.
The program has a compilation error because we cannot assign radius to radius.

The object is created with new keyword

1 Mark(s)

None of these
Depends on the code
At Compile-time
At run-time

A package is a collection of

1 Mark(s)

Classes and Interfaces
Classes
Editing tools
Editing tools and Interfaces
Interfaces

Choose the correct statement. Restriction on static methods are: I. They can only call other static methods.
II. They must only access static data.
III. They cannot refer this or super in any way.

1 Mark(s)

Only (I)
Only (III)
(II) and (III)
(I), (II) and (III)
(I) and (II)