Luis Garcia
Quiz by , created more than 1 year ago

Este es un test de prueba para los estudientes que quieren provar sus conocimientos para presentar el examen de certificación de JAVA

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Luis Garcia
Created by Luis Garcia about 7 years ago
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Test de prueba para Examen de certificación

Question 1 of 40

1

Which of these statements are true. Select the two correct answers.

Select one or more of the following:

  • For each try block there must be at least one catch block defined.

  • A try block may be followed by any number of finally blocks.

  • A try block must be followed by at least one finally or catch block.

  • If both catch and finally blocks are defined, catch block must precede the finally block.

Explanation

Question 2 of 40

1

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

Select one of the following:

  • static

  • final

  • abstract

  • native

  • volatile

  • transient

Explanation

Question 3 of 40

1

Which of the following are correct. Select the one correct answer.

Select one of the following:

  • An import statement, if defined, must always be the first non-comment statement of the file.

  • Private members are accessible to all classes in the same package.

  • An abstract class can be declared as final.

  • Local variables cannot be declared as static

Explanation

Question 4 of 40

1

. What is the result of compiling and running the following program.

public class Test {
public static void main (String[] args){
String str1 = "abc";
String str2 = "def";
String str3 = str1.concat(str2);

str1.concat(str2);
System.out.println(str1);
}
}

Select one of the following:

  • abc

  • def

  • abcabc

  • abcdef

  • defabc

  • abcdefdef

Explanation

Question 5 of 40

1

Assume that class A extends class B, which extends class C. Also all the three classes implement the method test(). How can a method in a class A invoke the test() method defined in class C (without creating a new instance of class C). Select the one correct answer.

Select one of the following:

  • test();

  • super.test();

  • super.super.test();

  • ::test();

  • C.test();

  • It is not possible to invoke test() method defined in C from a method in A.

Explanation

Question 6 of 40

1

Which keyword when applied on a method indicates that only one thread should execute the method at a time. Select the one correct answer.

Select one of the following:

  • transient

  • volatile

  • synchronized

  • native

  • static

  • final

Explanation

Question 7 of 40

1

In which all cases does an exception gets generated. Select the two correct answers.
int i = 0, j = 1;

Select one or more of the following:

  • if((i == 0) || (j/i == 1))

  • if((i == 0) | (j/i == 1))

  • if((i != 0) && (j/i == 1))

  • if((i != 0) & (j/i == 1))

Explanation

Question 8 of 40

1

If a base class has a method defined as void method() { }
Which of the following are legal prototypes in a derived class of this class.
Select the two correct answers.

Select one or more of the following:

  • void method() { }

  • int method() { return 0;}

  • void method(int i) { }

  • private void method() { }

Explanation

Question 9 of 40

1

Assuming the declaration String s = new String(“xyz”);
Which of the following statements would compile. Select the one correct answer.

Select one of the following:

  • s = 2 * s;

  • int i = s[0];

  • s = s + s;

  • s = s >> 2;

  • None of the above.

Explanation

Question 10 of 40

1

Which of the following are legal identifier names in Java. Select the two correct answers.

Select one or more of the following:

  • 1. %abcd

  • 2. $abcd

  • 3. 1abcd

  • 4. package

  • 5. _a_long_name

Explanation

Question 11 of 40

1

What gets printed when the following code is compiled and run. Select the one correct answer.
public class test {
public static void main(String args[]) {
int i = 1;
do {
i--;
} while (i > 2);
System.out.println(i);
}
}

Select one of the following:

  • 0

  • 1

  • 2

  • -1

Explanation

Question 12 of 40

1

Which of the following are legal array declarations. Select the three correct answers.

Select one or more of the following:

  • int i[5][];

  • int i[][];

  • int []i[];

  • int [5][5];

  • int[][]a;

Explanation

Question 13 of 40

1

What all gets printed when the following gets compiled and run. Select the two correct answers.
public class test {
public static void main(String args[]) {
String s1 = "abc";
String s2 = "abc";
if(s1 == s2)
System.out.println(1);
else
System.out.println(2);
if(s1.equals(s2))
System.out.println(3);
else
System.out.println(4);
}
}

Select one or more of the following:

  • 1

  • 2

  • 3

  • 4

Explanation

Question 14 of 40

1

What all gets printed when the following gets compiled and run. Select the three correct answers.
public class test {
public static void main(String args[]) {
int i=1, j=1;
try {
i++;
j--;
if(i/j > 1)
i++;
}
catch(ArithmeticException e) {
System.out.println(0);
}
catch(ArrayIndexOutOfBoundsException e) {
System.out.println(1);
}
catch(Exception e) {
System.out.println(2);
}
finally {
System.out.println(3);
}
System.out.println(4);
}
}

Select one or more of the following:

  • 0,1,2

  • 1,2,3

  • 0,3,4

  • 3,2,4

Explanation

Question 15 of 40

1

What all gets printed when the following program is compiled and run. Select the one correct answer.
public class test {
public static void main(String args[]) {
int i=0, j=2;
do {
i=++i;
j--;
} while(j>0);
System.out.println(i);
}
}

Select one of the following:

  • 1

  • The program does not compile because of statement “i=++i;”

  • 0

  • 2

Explanation

Question 16 of 40

1

What all gets printed when the following program is compiled and run. Select the two correct answers.
public class test {
public static void main(String args[]) {
int i, j=1;
i = (j>1)?2:1;
switch(i) {
case 0: System.out.println(0); break;
case 1: System.out.println(1);
case 2: System.out.println(2); break;
case 3: System.out.println(3); break;
}
}
}

Select one of the following:

  • 1,3

  • 2,1

  • 1,2

  • 3,2

Explanation

Question 17 of 40

1

Which of the following is true. Select the two correct answers.

Select one or more of the following:

  • A class that is abstract may not be instantiated.

  • The final keyword indicates that the body of a method is to be found elsewhere. The code is written in non-Java language, typically in C/C++.

  • A static variable indicates there is only one copy of that variable.

  • A method defined as private indicates that it is accessible to all other classes in the same package.

Explanation

Question 18 of 40

1

. Which of the following is correct? Select the correct answer.

Select one of the following:

  • The native keyword does not indicates that the method is implemented in another language like C/C++

  • The only statements that can appear before an import statement in a Java file are comments.

  • The method definitions inside interfaces are public and abstract. They cannot be private or protected.

  • A class constructor may have public or protected keyword before them, nothing else.

Explanation

Question 19 of 40

1

What gets printed when the following code is compiled and run with the following command: java test 2
Select the one correct answer.
public class test {
public static void main(String args[]) {
Integer intObj=Integer.valueOf(args[args.length-1]);
int i = intObj.intValue();
if(args.length > 1)
System.out.println(i);
if(args.length > 0)
System.out.println(i - 1);
else
System.out.println(i - 2);
}
}

Select one of the following:

  • test

  • test -1

  • 1

  • 0

  • 2

Explanation

Question 20 of 40

1

What is the default priority of a newly created thread.

Select one of the following:

  • MIN_PRIORITY (which is defined as 1 in the Thread class.)

  • NORM_PRIORITY (which is defined as 5 in the Thread class.)

  • A thread inherits the priority of its parent thread.

  • MAX_PRIORITY (which is defined as 10 in the Thread class.)

Explanation

Question 21 of 40

1

What should be done to invoke the run() method on a thread for an object derived from the Thread class. Select the one correct answer.

Select one of the following:

  • The run() method should be directly invoked on the Object.

  • The start() method should be directly invoked on the Object.

  • The creation of the object using the new operator would create a new thread and invoke its run() method.

  • The init() method should be directly invoked on the Object.

Explanation

Question 22 of 40

1

Select the one most appropriate answer. What is the purpose of method parseInt defined in Integer class.

Select one of the following:

  • The method converts an integer to a String.

  • The method is used to convert String to an integer, assuming that the String represents an integer.

  • The method is used to convert String to Integer class, assuming that the String represents an integer.

  • The method converts the Integer object to a String.

Explanation

Question 23 of 40

1

In implementing two classes Employee and Manager, such that each Manager is an Employee, what should be the relationship between these classes. Select the one correct answer.

Select one of the following:

  • Manager class should include the Employee class as a data member.

  • Manager should be the base class of Employee class.

  • Employee should be the base class of Manager class.

Explanation

Question 24 of 40

1

What gets printed when the following program is compiled and run. Select the one correct answer.
public class incr {
public static void main(String args[]) {
int i , j;
i = j = 3;
int n = 2 * ++i;
int m = 2 * j++;
System.out.println(i + " " + j + " " + n + " " + m);
}
}

Select one of the following:

  • 4 4 8 8

  • 4 4 8 6

  • 4 4 6 6

  • 4 3 8 6

  • 4 4 6 8

Explanation

Question 25 of 40

1

The class Hashtable is used to implement which collection interface. Select the one correct answer.

Select one of the following:

  • set

  • Map

  • Table

  • SortedSet

Explanation

Question 26 of 40

1

Which of these are legal identifiers. Select the three correct answers.

Select one or more of the following:

  • number_1

  • number_a

  • $1234

  • -volatile

Explanation

Question 27 of 40

1

Which of these are not legal identifiers. Select the two correct answers.

Select one or more of the following:

  • 1alpha

  • _abcd

  • xy+abc

  • transient

  • account-num

  • very_long_name

Explanation

Question 28 of 40

1

How many bytes are used to represent the primitive data type int in Java. Select the one correct answer.

Select one of the following:

  • 4

  • 8

  • 2

  • 1

Explanation

Question 29 of 40

1

What would happen when the following is compiled and executed. Select the one correct answer.
public class Compare {
public static void main(String args[]) {
int x = 10, y;
if(x < 10) y = 1;
if(x>= 10) y = 2;
System.out.println("y is " + y);
}
}

Select one of the following:

  • The program compiles and prints y is 0 when executed.

  • The program compiles and prints y is 1 when executed.

  • The program does not compile complaining about y not being initialized.

  • The program compiles and prints y is 2 when executed.

  • The program throws a runtime exception.

Explanation

Question 30 of 40

1

Which of the following are legal Java programs. Select the four correct answers.

Select one or more of the following:

  • // The comments come before the package
    package pkg;
    import java.awt.*;
    class C{}

  • package pkg;
    import java.awt.*;
    class C{}

  • package pkg1;
    package pkg2;
    import java.awt.*;
    class C{}

  • package pkg;
    import java.awt.*;

  • import java.awt.*;
    package pkg;
    class C {}

  • import java.awt.*;
    class C{}

Explanation

Question 31 of 40

1

What all gets printed on the standard output when the class below is compiled and executed by entering “java test lets see what happens”. Select the two correct answers.
public class test {
public static void main(String args[]) {
System.out.println(args[0]+" "+args.length);
}
}

Select one or more of the following:

  • java

  • test

  • lets

  • 4

  • 5

  • 3

Explanation

Question 32 of 40

1

What happens when the following program is compiled and run. Select the one correct answer.
public class example {
int i[] = {0};
public static void main(String args[]) {
int i[] = {1};
change_i(i);
System.out.println(i[0]);
}
public static void change_i(int i[]) {
int j[] = {2};
i = j;
}
}

Select one of the following:

  • The program does not compile.

  • The program prints 0

  • The program prints 1

  • The program prints 4

  • The program prints 2

Explanation

Question 33 of 40

1

Which of the following are keywords in Java. Select the two correct answers.

Select one or more of the following:

  • friend

  • NULL

  • implement

  • synchronized

  • throws

Explanation

Question 34 of 40

1

Which of these are Java keywords. Select the five correct answers

Select one or more of the following:

  • TRUE

  • volatile

  • transient

  • native

  • interface

  • then

  • new

Explanation

Question 35 of 40

1

What is the minimum value of char type. Select the one correct answer.

Select one of the following:

  • -215

  • 0

  • -215-1

  • -28

Explanation

Question 36 of 40

1

What is the legal range of values for a variable declared as a byte. Select the one correct answer.

Select one of the following:

  • 0 to 256

  • 0 to 255

  • -128 to 127

  • -128 to 128

  • -127 to 128

  • -215 to 215 – 1

Explanation

Question 37 of 40

1

What would happen when the following is compiled and executed. Select the one correct answer
class example {
int x;
int y;
String name;
public static void main(String args[]) {
example pnt = new example();
System.out.println("pnt is " + pnt.name + " " + pnt.x + " " + pnt.y);
}
}

Select one of the following:

  • The program does not compile because x, y and name are not initialized.

  • The program throws a runtime exception as x, y, and name are used before initialization

  • The program prints pnt is 0 0.

  • The program prints pnt is null 0 0.

  • The program prints pnt is NULL false false

Explanation

Question 38 of 40

1

What would be the results of compiling and running the following class. Select the one correct answer.
class test {
public static void main() {
System.out.println("test");
}
}

Select one of the following:

  • The program does not compile as there is no main method defined.

  • The program compiles and runs generating an output of “test”

  • The program compiles and runs but does not generate any output.

  • The program compiles but does not run.

Explanation

Question 39 of 40

1

. What happens when the following program is compiled and executed with the command – java test. Select the one correct answer.
class test {
public static void main(String args[]) {
if(args.length > 0)
System.out.println(args.length);
}
}

Select one of the following:

  • The program compiles and runs but does not print anything.

  • The program compiles and runs and prints 2

  • The program compiles and runs and prints 0

  • The program compiles and runs and prints 1

  • The program does not compile

Explanation

Question 40 of 40

1

What is the result of compiling and running this program? Select the one correct answer.

public class test {
public static void main(String args[]) {
int i, j;
int k = 0;
j = 2;
k = j = i = 1;
System.out.println(k);
}
}

Select one of the following:

  • The program does not compile because of the statement k = j = i = 1;

  • The program does not compile as k is being read without being initialized.

  • The program compiles and runs printing 0.

  • The program compiles and runs printing 2.

  • The program compiles and runs printing 1.

Explanation

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