Luis Garcia
Quiz por , criado 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
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Test de prueba para Examen de certificación

Questão 1 de 40

1

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

Selecione uma ou mais das seguintes:

  • 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.

Explicação

Questão 2 de 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.

Selecione uma das seguintes:

  • static

  • final

  • abstract

  • native

  • volatile

  • transient

Explicação

Questão 3 de 40

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 4 de 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);
}
}

Selecione uma das seguintes:

  • abc

  • def

  • abcabc

  • abcdef

  • defabc

  • abcdefdef

Explicação

Questão 5 de 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.

Selecione uma das seguintes:

  • 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.

Explicação

Questão 6 de 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.

Selecione uma das seguintes:

  • transient

  • volatile

  • synchronized

  • native

  • static

  • final

Explicação

Questão 7 de 40

1

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

Selecione uma ou mais das seguintes:

  • if((i == 0) || (j/i == 1))

  • if((i == 0) | (j/i == 1))

  • if((i != 0) && (j/i == 1))

  • if((i != 0) & (j/i == 1))

Explicação

Questão 8 de 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.

Selecione uma ou mais das seguintes:

  • void method() { }

  • int method() { return 0;}

  • void method(int i) { }

  • private void method() { }

Explicação

Questão 9 de 40

1

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

Selecione uma das seguintes:

  • s = 2 * s;

  • int i = s[0];

  • s = s + s;

  • s = s >> 2;

  • None of the above.

Explicação

Questão 10 de 40

1

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

Selecione uma ou mais das seguintes:

  • 1. %abcd

  • 2. $abcd

  • 3. 1abcd

  • 4. package

  • 5. _a_long_name

Explicação

Questão 11 de 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);
}
}

Selecione uma das seguintes:

  • 0

  • 1

  • 2

  • -1

Explicação

Questão 12 de 40

1

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

Selecione uma ou mais das seguintes:

  • int i[5][];

  • int i[][];

  • int []i[];

  • int [5][5];

  • int[][]a;

Explicação

Questão 13 de 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);
}
}

Selecione uma ou mais das seguintes:

  • 1

  • 2

  • 3

  • 4

Explicação

Questão 14 de 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);
}
}

Selecione uma ou mais das seguintes:

  • 0,1,2

  • 1,2,3

  • 0,3,4

  • 3,2,4

Explicação

Questão 15 de 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);
}
}

Selecione uma das seguintes:

  • 1

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

  • 0

  • 2

Explicação

Questão 16 de 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;
}
}
}

Selecione uma das seguintes:

  • 1,3

  • 2,1

  • 1,2

  • 3,2

Explicação

Questão 17 de 40

1

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

Selecione uma ou mais das seguintes:

  • 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.

Explicação

Questão 18 de 40

1

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

Selecione uma das seguintes:

  • 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.

Explicação

Questão 19 de 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);
}
}

Selecione uma das seguintes:

  • test

  • test -1

  • 1

  • 0

  • 2

Explicação

Questão 20 de 40

1

What is the default priority of a newly created thread.

Selecione uma das seguintes:

  • 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.)

Explicação

Questão 21 de 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.

Selecione uma das seguintes:

  • 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.

Explicação

Questão 22 de 40

1

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

Selecione uma das seguintes:

  • 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.

Explicação

Questão 23 de 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.

Selecione uma das seguintes:

  • 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.

Explicação

Questão 24 de 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);
}
}

Selecione uma das seguintes:

  • 4 4 8 8

  • 4 4 8 6

  • 4 4 6 6

  • 4 3 8 6

  • 4 4 6 8

Explicação

Questão 25 de 40

1

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

Selecione uma das seguintes:

  • set

  • Map

  • Table

  • SortedSet

Explicação

Questão 26 de 40

1

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

Selecione uma ou mais das seguintes:

  • number_1

  • number_a

  • $1234

  • -volatile

Explicação

Questão 27 de 40

1

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

Selecione uma ou mais das seguintes:

  • 1alpha

  • _abcd

  • xy+abc

  • transient

  • account-num

  • very_long_name

Explicação

Questão 28 de 40

1

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

Selecione uma das seguintes:

  • 4

  • 8

  • 2

  • 1

Explicação

Questão 29 de 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);
}
}

Selecione uma das seguintes:

  • 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.

Explicação

Questão 30 de 40

1

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

Selecione uma ou mais das seguintes:

  • // 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{}

Explicação

Questão 31 de 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);
}
}

Selecione uma ou mais das seguintes:

  • java

  • test

  • lets

  • 4

  • 5

  • 3

Explicação

Questão 32 de 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;
}
}

Selecione uma das seguintes:

  • The program does not compile.

  • The program prints 0

  • The program prints 1

  • The program prints 4

  • The program prints 2

Explicação

Questão 33 de 40

1

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

Selecione uma ou mais das seguintes:

  • friend

  • NULL

  • implement

  • synchronized

  • throws

Explicação

Questão 34 de 40

1

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

Selecione uma ou mais das seguintes:

  • TRUE

  • volatile

  • transient

  • native

  • interface

  • then

  • new

Explicação

Questão 35 de 40

1

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

Selecione uma das seguintes:

  • -215

  • 0

  • -215-1

  • -28

Explicação

Questão 36 de 40

1

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

Selecione uma das seguintes:

  • 0 to 256

  • 0 to 255

  • -128 to 127

  • -128 to 128

  • -127 to 128

  • -215 to 215 – 1

Explicação

Questão 37 de 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);
}
}

Selecione uma das seguintes:

  • 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

Explicação

Questão 38 de 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");
}
}

Selecione uma das seguintes:

  • 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.

Explicação

Questão 39 de 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);
}
}

Selecione uma das seguintes:

  • 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

Explicação

Questão 40 de 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);
}
}

Selecione uma das seguintes:

  • 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.

Explicação