MCQ Coding Questions

1 How to invoke constructor in Servlets.

Using servlet Container

By Init() method

Can’t invoke

None of the above.

2 Which method retrieves the body of the request as binary data.

None of the above

request.getInputStream()

response.getInputStream()

New InputStream()

3What is the output of below program?

public class StringDemo {
    public static void main(String args[]){
        // The line below this gives an output
        // \u000d System.out.println("comment executed");
    }
}

Compile Exception

comment executed

Empty

The line below this gives an output

4What is the result of this program.

public class Demo {
    public static void main(String args[]){
        System.out.println(3*0.1 == 0.3);
    }
}

True

False

Compile time error

Runtime error

5Output for below program

class A {
    static int i = 1111;
    static
    {
        i = i-- - --i;
    }
    {
        i = i++ + ++i;
    }
}
class B extends A
{
    static
    {
        i = --i - i--;
    }
    {
        i = ++i + i++;
    }
}
 class Demo
{
    public static void main(String[] args)
    {
        B b = new B();
        System.out.println(b.i);
    }
}

0

9

6

15

6What is the output of below code

try {
  File file = new File("path");
  FileInputStream fis = new FileInputStream(file);
  String s = "inside";
} catch (FileNotFoundException e) {
  e.printStackTrace();
  System.out.println(s);
}

Inside

Path

File not found exception

Compilation error

7What exception will be thrown by Double.parseDouble(null)

NumberFormatException

NullPointerException

ArithmeticException

DivisionByZero

8Select a commonly used runtime exception

NumberFormatException

NullPointerException

ArrayIndexOutOfBoundException

FileNotFoundException

9The regular expressions \d mean

Range of digits (0-9)

Range of digits (1-9)

A single digit

A Non digit

10Way to split string by new lines without empty lines is

String.split("\\r?\\n")

String.split("[\\r\\n]+")

String.split("[\\r\\n] ")

String.split(System.getProperty("line.separator"))

11Which of the below statement is true about LinkedList

to access an element in the middle, it has to search from the beginning of the list

Its elements can be accessed directly by index

adding or removing an element needs to move existing elements

None of the above

12What is the output of below code
String str = "abcd";
String repeated = StringUtils.repeat(str,3);

abcdabcdabcd

abcdabcdabcdabcd

abcd

abc

13What is the output of below code

String str = "Sep 17, 2013";
Date date = new SimpleDateFormat("MMMM d, yy", Locale.ENGLISH).parse(str);
System.out.println(date);

Tue Sep 17, 13

Tue Sep 17, 2013

September 17 00:00:00 EDT 2013

Tue Sep 17 00:00:00 EDT 2013

14Predict the output of following Java program?

class Test {
  int i;
}
class Main {
   public static void main(String args[]) {
     Test t;
     System.out.println(t.i);
}

Runtime error

Compile error

Garbage value

0

15What is the output of the following program ?

Class Test {
    public static void main(String[] args) {
        Test obj = new Test();
        obj.start();
    }
    void start() {
        String stra = ”do”;
            String strb = method(stra);
        System.out.print(“: ”+stra + strb);
    }
    String method(String stra) {
        stra = stra + ”good”;
        System.out.print(stra);
        return“ good”;
    }
}

dogood : dogood

dogood : dodogood

dogood : gooddogood

dogood : dogoodgood

16When we implement an interface method, it must be declared as:

Friend

Public

Protected

Private

17Output of following Java program?

class Main {
    public static void main(String args[]) { 
             System.out.println(fun());
    }
    int fun()
    {
      return 20;
    }
}

Garbage value

0

Compile error

20

18What is the output of below code

class Test {
public static void swap(Integer i, Integer j) {
      Integer temp = new Integer(i);
      i = j;
      j = temp;
   }
   public static void main(String[] args) {
      Integer i = new Integer(10);
      Integer j = new Integer(20);
      swap(i, j);
      System.out.println("i = " + i + ", j = " + j);
   }
}

 i = 10, j = 20

 i = 20, j = 10

i = 20, j = 20

i = 10, j = 10

19Predict the output
class Main {
    public static void main(String args[]) { 
            System.out.println(fun());
    } 
    static int fun(int x = 0)
    {
      return x;
    }
}

0

Garbage value

Compile error

Runtime error

20Predict the output of the following program.

class Test
{
    public static void main(String[] args)
    {
        StringBuffer a = new StringBuffer("geeks");
        StringBuffer b = new StringBuffer("forgeeks");
        a.delete(1,3);
        a.append(b);
        System.out.println(a);
    }
}

gsforgeeks

gksforgeeks

geksforgeeks

Compilation error

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