Java Interview Questions - Part1

Java aptitude/interview questions - Part 1

This is Objectives type java question with answers which will help fresh engineering graduates to crack the interview and java aptitude test.
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Question 1) Which of the following lines will compile without warning or error.
1) float f=1.3;
2) char c="a";
3) byte b=257;
4) boolean b=null;
5) int i=10;

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Question 2)
What will happen if you try to compile and run the following code
public class MyClass {
public static void main(String arguments[]) {
amethod(arguments);
}
public void amethod(String[] arguments) {
System.out.println(arguments);
System.out.println(arguments[1]);
}
}
1) error Can't make static reference to void amethod.
2) error method main not correct
3) error array must include parameter
4) amethod must be declared with String
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Question 3)
Which of the following will compile without error
1)
import java.awt.*;
package Mypackage;
class Myclass {}
2)
package MyPackage;
import java.awt.*;
class MyClass{}
3)
/*This is a comment */

package MyPackage;

import java.awt.*;

class MyClass{}

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Question 4)
A byte can be of what size
1) -128 to 127
2) (-2 power 8 )-1 to 2 power 8
3) -255 to 256
4)depends on the particular implementation of the Java Virtual machine

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Question 5)
What will be printed out if this code is run with the following command line?
java myprog good morning
public class myprog{

public static void main(String argv[])
{

System.out.println(argv[2])

}
}
1) myprog
2) good
3) morning
4) Exception raised: "java.lang.ArrayIndexOutOfBoundsException: 2"

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Question 6)

Which of the following are java reserved words?
1) if
2) then
3) goto
4) while
5) case
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Question 7)

Which of the following are legal identifiers
1) 2variable
2) variable2
3) _whatavariable
4) _3_
5) $anothervar
6) #myvar
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Question 8)
What will happen when you compile and run the following code?

public class MyClass{

static int i;

public static void main(String argv[]){

System.out.println(i);

}

}
1) Error Variable i may not have been initialized
2) null
3) 1
4) 0
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Question 9)
What will happen if you try to compile and run the following code?
public class Q {

public static void main(String argv[]){

int anar[]=new int[]{1,2,3};

System.out.println(anar[1]);

}

}
1) 1
2) Error anar is referenced before it is initialized
3) 2
4) Error: size of array must be defined

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Question 10)

What will happen if you try to compile and run the following code?
public class Q {

public static void main(String argv[]){

int anar[]=new int[5];

System.out.println(anar[0]);

}

}
1) Error: anar is referenced before it is initialized
2) null
3) 0
4) 5
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Question 11)

What will be the result of attempting to compile and run the following code?
abstract class MineBase {

abstract void amethod();

static int i;

}
public class Mine extends MineBase {

public static void main(String argv[]){

int[] ar=new int[5];

for(i=0;i < ar.length;i++)

System.out.println(ar[i]);

}

}
1) a sequence of 5 0's will be printed
2) Error: ar is used before it is initialized
3) Error Mine must be declared abstract
4) IndexOutOfBoundes Error
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Question 12)
What will be printed out if you attempt to compile and run the following code ?
int i=1;

switch (i) {

case 0:

System.out.println("zero");

break;

case 1:

System.out.println("one");

case 2:

System.out.println("two");

default:

System.out.println("default");

}
1) one
2) one, default
3) one, two, default
4) default
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Question 13)
What will be printed out if you attempt to compile and run the following code?
int i=9;

switch (i) {

default:

System.out.println("default");

case 0:

System.out.println("zero");

break;

case 1:

System.out.println("one");

case 2:

System.out.println("two");

}
1) default
2) default, zero
3) error default clause not defined
4) no output displayed
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Question 14)
Which of the following lines of code will compile without error
1)
int i=0;

if(i) {

System.out.println("Hello");

}
2)
boolean b=true;

boolean b2=true;

if(b==b2) {

System.out.println("So true");

}
3)
int i=1;

int j=2;

if(i==1|| j==2)

System.out.println("OK");
4)
int i=1;

int j=2;

if(i==1 &| j==2)

System.out.println("OK");