Certificación Java

Domain:Creating and Using Arrays

What will be the output of this program code?

public class Whiz{

public static void main(String[] args){

String[][] strs=new String[5][];

strs[1]=new String[2];

System.out.print(strs.length + strs[1].length);

}

}

• 2

• 7

• 4

• A null pointer exception is thrown

• Compilation fails

What will be the output of this program

public class Whiz{

public static void main(String[] args){

do{

int i=1;

System.out.print(i++ + "");

}while(i<=5);

}

}

• 11111

• An infinite loop

• compilation fails

• 12345

• 123456

Domain Java Basics

Which of the following will import only static members of java.util.Arrays

• static import java.util.Arrays;

• import java.util.Arrays.*;

• import java.util.Arrays;

• import static java.util.Arrays;

• import static java.util.Arrays.*;

Domain Handling Exceptions

Which of the following can be inserted at line2, to make this code compilable

1. public void exc() throws FileNotFoundException{

2. // INSERT CODE HERE

3.}

• throw new RuntimeException();

• throw new java.io.IOException();

• throw new Exception();

• throw new IOException():

• All of the above

Domain:Using Operators and Decision Constructs

Which of the following operator is used by Java to create an instance of class

• create

• instanceof

• new

• free

• None of the above

Dornain:Using Operators and Decision Constructs

Which of the following has higher operator precedence than "/" operator

• !

• +

• -

• *

• None of the above

Domain Java Basics

Consider the following content of a source code file

import myLibrary.*;

public class Whiz{

//code for the class

}

class Lab{

//code for the class ....

}

What could be the name of the java file containing this source?

• This can't be included in one source.

• This can be included in any file name with having java file extension

• Lab.java

• Whiz.java

Which can be used to fill the blank?

............................... is thrown by the JVM when there is a null reference to an object

• ClassCastException

• ArrayIndexOutOfBoundsException

• NumberFormatException

• IllegalArgumentException

• NullPointerException

Domain:Using Loop Constructs

What will be the output of this program?

public class Whiz{

public static void main(String args[]){

int x=2;

for(int x=0;x<3;x++){

System.out.print(x);

}

}

}

• 222

• 123

• 12

• 1234

• Compilation fails.

What is the output of the following code?

1. interface Nocturnal{

2. default boolean isBlind(){ return true; }

3.}

4. public class Owl implements Nocturnal{

5. public boolean isBlind(){ return false; }

6. public static void main(String[] args) {

7. Nocturnal nocturnal = (Nocturnal) new Owl();

8. System.out.println(nocturnal.isBlind());

9. }

10.}

• The code will not compile because of line 2.

• true

• The code will not compile because of line 5.

• false

• The code will not compile because of line7.