DECLARATION AND ACCESS CONTROL QUIZ

Choose the correct statementpublic class Circle{ private double radius; public Circle(double radius){ radius = radius; }}

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 we cannot assign radius to radius.

The program does not compile because Circle does not have a default constructor.

The program has a compilation error because it does not have a main method.

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What can directly access and change the value of the variable qusNo?package com.mypackage;public class Test{ private int qusNo = 100;}

Any class that extends Test.

None of these

Only the Test class.

Any class in com.mypackage package.

Any class.

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

This method is only accessible from inside the class itself and from inside all subclasses.

From within protected methods you do not have access to public methods.

This method is accessible from within the class itself and from within all classes defined in the same package as the class itself.

In a class, you cannot declare methods with a lower visibility than the visibility of the class in which it is defined.

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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}

static void add(int...args){}

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

void add(Integer... args){}

static void add(int args...){}

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

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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(); }}

None of these

static A

A block static

static block A

A

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

volatile

native

static

final

abstract

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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(); }}

BaseDerived

Derived

Exception is thrown at runtime

Compilation Error

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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;}

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

An object of B contains data fields k, m.

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

An object of B contains data fields j, m.

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A package is a collection of

Classes and Interfaces

Editing tools

Editing tools and Interfaces

Classes

Interfaces

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

Compile error at line 4 (invalid argument type for method main)

Compile error at line 1 (static x must be only accessed inside static methods)

Compile error at line 2 (must access x by writing Tester.x)

Compile error at line 3 (static methods can't make reference to non-static variables)

49

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