Interview Questions and Answers for 'Set' | Search Interview Question

Interview Questions and Answers - Order By Newest

Q11. Which are the sorted collections ?

Core Java

Ans. TreeSet and TreeMap

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections treemap treeset basic interview question basic frequent}

Q12. What will be the output of this code ?

Set mySet = new HashSet();
mySet.add("4567");
mySet.add("5678");
mySet.add("6789");
for(String s: mySet){
System.out.println(s);
}

Ans. It will print 4567,5678 and 6789 but Order cannot be predicted.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set hashset coding code}

Try 1 Question(s) Test

Q13. What will be the output of this code ?

Set mySet = new HashSet();
mySet.add("4567");
mySet.add("5678");
mySet.add("6789");
System.out.println(s.get(0));

Ans. This will give compile time error as we cannot retrieve the element from a specified index using Set. Set doesn't maintain elements in any order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set hashset coding code}

Try 1 Question(s) Test

Q14. What will be the output of the following code ?

enum Day {
MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY,SATURDAY,SUNDAY
}

public class BuggyBread1{
public static void main (String args[]) {
Set mySet = new TreeSet();
mySet.add(Day.SATURDAY);
mySet.add(Day.WEDNESDAY);
mySet.add(Day.FRIDAY);
mySet.add(Day.WEDNESDAY);
for(Day d: mySet){
System.out.println(d);
}
}
}

Core Java

Ans. WEDNESDAY
FRIDAY
SATURDAY

Only one FRIDAY will be printed as Set doesn't allow duplicates.Elements will be printed in the order in which constants are declared in the Enum. TreeSet maintains the elements in the ascending order which is identified by the defined compareTo method. compareTo method in Enum has been defined such that the constant declared later are greater than the constants declared prior.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding enum set treeset advanced}

Try 3 Question(s) Test

Q15. Explain Set Interface?

Core Java

Ans. It is a collection of element which cannot contain duplicate elements. The Set interface contains only methods inherited from Collection and adds the restriction that duplicate elements are prohibited.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set interface set}

Q16. What is the best practice configuration usage for files - pom.xml or settings.xml ?

Maven

Ans. The best practice guideline between settings.xml and pom.xml is that configurations in settings.xml must be specific to the current user and that pom.xml configurations are specific to the project.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve maven build technologies pom.xml settings.xml architecture technical architect technical lead build management build and release}

Try 1 Question(s) Test

Q17. What ate the getter and setter methods ?

Ans. getters and setters methods are used to store and manipulate the private variables in java beans. A getters as it has name, suggest retrieves the attribute of the same name. A setters are allows you to set the values of the attributes.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java java beans getter setter}

Q18. Can we use Ordered Set for performing Binary Search ?

Ans. We need to access values on the basis of an index in Binary search which is not possible with Sets.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java sets set collections binary search}

Q19. What will be the output of this code ?

Set mySet = new TreeSet();
mySet.add("4567");
mySet.add("5678");
mySet.add("6789");
for(String s: mySet){
System.out.println(s);
}

Ans. 4567
5678
6789

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set treeset coding code}

Q20. public enum Day {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
THURSDAY, FRIDAY, SATURDAY
}

public class Test {
Set mySet = new HashSet();
mySet.add(Day.MONDAY);
mySet.add(Day.SUNDAY);
mySet.add(Day.SATURDAY);

for(Day d: mySet){
System.out.println(d);
}
}

Ans. SUNDAY
MONDAY
SATURDAY

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve enum set collections hashset coding code}

Try 3 Question(s) Test

Q21. What will be the output of the following code ?

enum Day {
   MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY,SATURDAY,SUNDAY
}

public class BuggyBread1{
   public static void main (String args[]) {
      Set mySet = new HashSet();
      mySet.add(Day.SATURDAY);
      mySet.add(Day.WEDNESDAY);
      mySet.add(Day.FRIDAY);
      mySet.add(Day.WEDNESDAY);
      for(Day d: mySet){
         System.out.println(d);
      }
   }
}

Ans. FRIDAY , SATURDAY and WEDNESDAY will be printed but the order cannot be determined.

Only one FRIDAY will be printed as Set doesn't allow duplicates. Order cannot be determined as HashSet doesn't maintain elements in a particular order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding enum set hashset}

Try 3 Question(s) Test

Q22. public class BuggyBread1{

public static void main (String args[]) {
Set<String> mySet = new TreeSet<String>();
mySet.add(""1"");
mySet.add(""2"");
mySet.add(""111"");
for(String d: mySet){
System.out.println(d);
}
}
}

Core Java

Ans. 1
111
2

TreeSet maintains the elements in the ascending order which is identified by the compareTo method. compareTo method in String has been defined such that it results in the natural alphabetic Order. Here the elements in the TreeSet are of String and not of Integer. In String Natural Order, 111 comes before 2 as ascii of 1st character first determines the order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding set treeset string integer}

Q23. public class BuggyBread1{

public static void main (String args[]) {
Set<Integer> mySet = new TreeSet<Integer>();
mySet.add(1);
mySet.add(2);
mySet.add(111);
for(Integer d: mySet){
System.out.println(d);
}
}
}

Core Java

Ans. 1
2
111

TreeSet maintains the elements in the ascending order which is identified by the compareTo method. compareTo method in Integer has been defined such that it results in the natural numerical Order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding set treeset}

Q24. How is HashSet maintained in memory by Java ?

Core Java

Ans. HashSet is maintained as HashMap by Java with values of the HashSet as Keys of the HashMap and value of the HashMap as the constant PRESENT.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve ebay java collections hashset hashmap expert}

Q25. What is classpath in a project?

Core Java

Ans. ClassPath is the path where Java looks for class files to resolve the dependencies. For example - If you are using a class "xyz" in your code and have specified the respective import, Where should Java look for the definition of xyz. Java determines using the class path settings.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java classpath classpath settings Asked in 2 Companies}

Q26. Name few classes that implement Set interface ?

Ans. http://www.buggybread.com/2015/02/java-collections-classes-that-implement_78.html

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set}

Q27. How many elements will be there in TreeSet after the last line and Why ?

TreeSet set = new TreeSet();
set .add(new String("abc"));
set .add(new String("abc"));

Core Java

Ans. One.

As we haven't specified the type of TreeSet, it being evaluated with the first element insertion. Once it's identified that it's of type String and as no comparator has been defined, the comparison is done using the String compareTo method. String compareTo method compares the elements by the content / value.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java set treeset string compareto coding code}

Q28. If we add Enum constants to a sorted collection ( Treemap , TreeSet ), What will be the order in which they will be maintained ?

a. Sorted Collection wont maintain them in any order.
b. Insertion Order
c. Order in which constants are declared.
d. Natural Sorting Order.

Ans. Order in which constants are declared.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve enum collections sorted collections treemap treeset compareto comparable java}

Q29. Write a method to convert all elements of a set to lower case.

Core Java

Ans. http://javasearch.buggybread.com/CodeSnippets/searchCodeSamples.php?keyword=Method+to+convert+all+elements+of+a+collection&category=code

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve code coding string String.toLowerCase set collections}

Q30. Write code to sort elements of a set

Ans. http://javasearch.buggybread.com/CodeSnippets/searchCodeSamples.php?&category=code&searchOption&keyword=952

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve set collections sorting treeset code coding}

Q31. What is unmodifiable set / unmodifiable map ? How can we create one ?

Ans. It is an unmodifiable / read only view of the underlying collection. We can use

Collections.unmodifiableSet(Set set)
Collections.unmodifiableMap(Map map)
Collections.unmodifiableCollection(Collection collection)

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve collections set unmodifiable set map unmodifiable map unmodifiablemap unmodifiableset Collections.unmodifiableCollection Collections.unmodifiableMap Collections.unmodifiableSet}

Q32. Is it advisable to set the member variables through constructors instead of setting them through setters ?

Ans. Yes , If the values to be set are known at the time of initialization and doesn't involve polymorphic behavior.If it's using Dependency Injection , then Constructor injection must be available. If it suffice the above conditions, then definitely its advisable to have them set through constructor as they eagerly load the values into the memory and save it fro multiple values assignment ( one through default constructor and then through assignment )

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve constructor setter vs constructor}

Frequently asked in Alibaba (Based on 2 feedback)

Q33. What is the best Memory setting for JVM ?

Core Java

Ans. In Java JVM memory settings is done by use the arguments -Xms -Xmx. Use M or G after the numbers for indicating Megs and Gigs of bytes respectively. -Xms indicates the minimum and -Xmx the maximum.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve jvm memory management jvm best memory setting Asked in 1 Companies intermediate}

Frequently asked in Accenture.

Q34. What is your biggest achievement at work ?

General

Ans. [Open Ended Answer]

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve general question non technical question Asked in 20 Companies frequent}

Q35. What is an Asset store ?

IBM WCS

Ans. Asset stores are collections of sharable resources (business artifacts, business processes and storefront assets) that can be leveraged in other stores.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve asset store}

Q36. What are the core OOPs concepts ?

Core Java

Ans. Abstraction, Encapsulation, Polymorphism , Composition and Inheritance

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve core oops concepts Asked in 65 Companies basic frequent}

Q37. What is a mutator in Java?

Core Java

Ans. Mutator is another name for setter methods, i.e the method allows for mutating the property of an object and eventually the state of the object.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve setter method mutator}

Q38. What is the quickest way to find count of duplicate elements in an arraylist, without using iteration or loops ?

Core Java

Ans. We can copy the elements to a Set and then find the difference of count between ArrayList and Set. As Set don't allow duplicates , they will be removed in the set.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve collections arraylist set}

Q39. How can we set a key within Redis ?

Redis

Ans. SET <KEY_NAME> <VALUE>

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve redis setting a key}

Q40. As root, if you have to assign the owner for the file and set only read permission for the owner, Write a unix command to do it.

Unix

Ans. chmod 477

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve unix commands setting file permissions chown chmod}

Search Interview Questions

Help us and Others Improve. Please let us know the questions asked in any of your previous interview.