Interview Questions and Answers - Order By Newest Q691. Which is the abstract parent class of FileWriter ? Core Java
Ans. OutputStreamWriter Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   filewriter   outputstreamwriter  file handling Q692. Which class is used to read streams of raw bytes from a file? Core Java
Ans. FileInputStream Sample Code for FileInputStream Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   fileinputstream  file handling Q693. Which is the Parent class of FileInputStream ? Core Java
Ans. InputStream Sample Code for InputStream Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   fileinputstream   inputstream  file handling Q694. Which of the following code is correct ?
a.
FileWriter fileWriter = new FileWriter("../file.txt");
File file = new File(fileWriter );
BufferedWriter bufferedOutputWriter = new BufferedWriter(fileWriter);
b.
BufferedWriter bufferedOutputWriter = new BufferedWriter("../file.txt");
File file = new File(bufferedOutputWriter );
FileWriter fileWriter = new FileWriter(file);
c.
File file = new File("../file.txt");
FileWriter fileWriter = new FileWriter(file);
BufferedWriter bufferedOutputWriter = new BufferedWriter(fileWriter);
d.
File file = new File("../file.txt");
BufferedWriter bufferedOutputWriter = new BufferedWriter(file);
FileWriter fileWriter = new FileWriter(bufferedOutputWriter ); Core Java
Ans. c.
File file = new File("../file.txt");
FileWriter fileWriter = new FileWriter(file);
BufferedWriter bufferedOutputWriter = new BufferedWriter(fileWriter); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   coding   code   filewriter   bufferedwriter   scjp   ocjp  file handling Q695. Which exception should be handled in the following code ?
File file = new File("../file.txt");
FileWriter fileWriter = new FileWriter(file); Core Java
Ans. IOException Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   coding   code   exception   ioexception  file handling Q696. Which exceptions should be handled with the following code ?
FileOutputStream fileOutputStream = new FileOutputStream(new File("newFile.txt"));
Ans. FileNotFoundException Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   coding   code   scjp   ocjp   filenotfoundexception   fileoutputstream  file handling Q697. What is the problem with this code ?
class BuggyBread1 {
private BuggyBread2 buggybread2;
public static void main(String[] args){
try {
BuggyBread1 buggybread1 = new BuggyBread1();
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(new File("newFile.txt")));
objectOutputStream.writeObject(buggybread1);
} catch (Exception e) {
e.printStackTrace();
}
}
} Core Java
Ans. Though we are trying to serialize BuggyBread1 object but we haven't declared the class to implement Serializable.
This will throw java.io.NotSerializableException upon execution. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   coding   code   serialization   notserializableexception   exception   file handling Q698. Will this code run fine if BuggyBread2 doesn't implement Serializable interface ?
class BuggyBread1 implements Serializable{
private BuggyBread2 buggybread2 = new BuggyBread2();
public static void main(String[] args){
try {
BuggyBread1 buggybread1 = new BuggyBread1();
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(new File("newFile.txt")));
objectOutputStream.writeObject(buggybread1);
} catch (Exception e) {
e.printStackTrace();
}
}
} Core Java
Ans. No, It will throw java.io.NotSerializableException. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   coding   code   serialization   notserializableexception   exception   file handling Q699. Will this code work fine if BuggyBread2 doesn't implement Serializable ?
class BuggyBread1 extends BuggyBread2 implements Serializable{
private int x = 5;
public static void main(String[] args){
try {
BuggyBread1 buggybread1 = new BuggyBread1();
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(new File("newFile.txt")));
objectOutputStream.writeObject(buggybread1);
} catch (Exception e) {
e.printStackTrace();
}
}
} Core Java
Ans. Yes. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   file   fileio   coding   code   serialization   yesno  file handling Q700. Difference between Class Path and Build Path ? Core Java
Ans. The build path is used for building your application. It contains all of your source files and all Java libraries that are required to compile the application.
The classpath is used for executing the application. This includes all java classes and libraries that are needed to run the java application. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q701. Will this code Work ? If not , Why ? java.util.Calendar c = new java.util.Calendar(); Core Java
Ans. No. It gives the error "Cannot Instantiate the type Calendar". Calendar is an abstract class and hence Calendar object should be instantiated using Calendar.getInstance(). Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   date   calendar   abstract class   yes-no Q702. Is java.util.Date an abstract Class ? Is java.util.Calendar an abstract Class ? Core Java
Ans. Date is not a abstract class whereas Calendar is. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   date   calendar   abstract class Q703. What will the following code print ? java.util.Calendar c = java.util.Calendar.getInstance(); c.add(Calendar.MONTH, 5); System.out.println(c.getTime()); Core Java
Ans. Date and Time after 5 months from now. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   date   calendar   scjp   ocjp   coding   code Q704. Which of the following code is correct ? a. DateFormat df = DateFormat.getInstance(); b. DateFormat df = DateFormat.getDateInstance(); c. DateFormat df = DateFormat.getInstance(DateFormat.FULL); d. DateFormat df = DateFormat.getDateInstance(DateFormat.FULL); Core Java
Ans. All except c are correct. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   date   dateformat Q705. What is the use of parse method in DateFormat ?
Ans. It is used to parse String to get the Date Object with initialized date. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   date   dateformat Q706. Which of the following is not a valid java.util.Locale initialization ? a. new Locale () b. new Locale ( String language ) c. new Locale ( String language , String country ) Core Java
Ans. a i.e new Locale() Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   locale   java.util Q707. Which of the following is not a valid NumberFormat initialization ? a. NumberFormat.getInstance() b. NumberFormat.getDateInstance() c. NumberFormat.getCurrencyInstance() d. NumberFormat.getNumberInstance() Core Java
Ans. b i.e NumberFormat.getDateInstance() Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   java.util.numberformat Q708. What will the following code print ? public static void main(String[] args){ Integer i1 = new Integer("1"); Integer i2 = new Integer("2"); Integer i3 = Integer.valueOf("3"); int i4 = i1 + i2 + i3; System.out.println(i4); } Core Java
Ans. 6 Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   int   integer   scjp   ocjp Q709. Which of the following syntax are correct ?a. LinkedList<Integer> l=new LinkedList<int>();b. List<Integer> l=new LinkedList<int>();c. LinkedList<Integer> l=new LinkedList<Integer>();d. List<Integer> l = new LinkedList<Integer>(); Core Java
Ans. All are correct. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   generics   linkedlist   list   collections basic Q710. Which of the following code is correct ? a. Date date = DateFormat.newInstance(DateFormat.LONG, Locale.US).parse(str); b. Date date = DateFormat.newInstance(DateFormat.LONG, Locale.US).format(str); c. Date date = DateFormat.getDateInstance(DateFormat.LONG, Locale.US).parse(str); Core Java
Ans. c Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   java.util   date   dateformat Q711. Which methods of the Pattern class have equivalent methods in the String class? Core Java
Ans. split() and macthes() Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   io   string class   string   patternVery Frequently asked. Favorite question in walkins and telephonic interviews. Usually among first few questions. Asked in different variants. Must know for intermediate and expert professionals.Among Top 10 frequently asked questions. Q712. What is rule regarding overriding equals and hashCode method ? Core Java
Ans. A Class must override the hashCode method if its overriding the equals method. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   hashcode  hash code   equals   collections Asked in 44 Companies intermediate   frequent Try 1 Question(s) Test Q713. What is the difference between Collection and Collections ? Core Java
Ans. Collection is an interface whereas Collections is a utility class. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections Asked in 1 Companies Q714. How can we reverse the order in the TreeMap ?
Ans. Using Collections.reverseOrder() Map tree = new TreeMap(Collections.reverseOrder()); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   map   treemap Try 1 Question(s) Test Q715. TreeMap orders the elements on which field ?
Ans. Keys Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   map   treemap Q716. How TreeMap orders the elements if the Key is a String ?
Ans. As String implements Comparable, It refers to the String compareTo method to identify the order relationship among those elements. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   comparable interface   treemap   compareto Q717. Can we add heterogeneous elements into TreeMap ?
Ans. No, Sorted collections don't allow addition of heterogeneous elements as they are not comparable. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   comparable interface   treemap Q718. Will it create any problem if We add elements with key as user defined object into the TreeMap ?
Ans. It won't create any problem if the objects are comparable i.e we have that class implementing Comparable interface. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   treemap   comparable interface Q719. Can we have null keys in TreeMap ? Core Java
Ans. No, results in exception. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   treemap Asked in 6 Companies Basic   frequent Q720. Can value be null in TreeMap ? Core Java
Ans. Yes. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java   collections   treemap   yes-no