Get Job-ready: Java Course with 45+ Real-time Projects! - Learn Java
Dive into the exciting world of wildcards in Java and test your mastery with this interactive quiz! Wildcards offer a powerful tool in your Java programming toolbox, promoting code flexibility and reusability. This engaging quiz goes beyond multiple-choice, delving deeper into various wildcard concepts.
By tackling these challenges, you’ll not only identify areas where you might need to refine your understanding, but also solidify your foundational knowledge of wildcards.
So, whether you’re a seasoned Java developer looking to refresh your skills or a curious beginner embarking on your programming adventure, this quiz is your chance to assess your grasp of wildcards in action. Ready to conquer wildcards? Take the quiz and embark on a rewarding learning experience!
Quiz Summary
0 of 15 Questions completed
Questions:
Information
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading…
You must sign in or sign up to start the quiz.
You must first complete the following:
Results
Results
0 of 15 Questions answered correctly
Your time:
Time has elapsed
You have reached 0 of 0 point(s), (0)
Earned Point(s): 0 of 0, (0)
0 Essay(s) Pending (Possible Point(s): 0)
Categories
- Not categorized 0%
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- Current
- Review / Skip
- Answered
- Correct
- Incorrect
-
Question 1 of 15
1. Question
Which type of wildcard should be used to relax the data type restriction ?
CorrectIncorrect -
Question 2 of 15
2. Question
class Main {
public static void main ( String args [ ] )
{
List<String> list = Arrays.aslist(“Sunday”,”Monday”,”Tuesday”);
print(list);
List<Object> list2 = Arrays.aslist(“Sunday”,”Monday”,”Tuesday”);
print(list2);
public static void print(List<?extend numbers> list)
{
System.out.println(list);
}
}
}
What will be the output of the program ?
CorrectIncorrect -
Question 3 of 15
3. Question
class WildCard {
public static void main ( String args [ ] )
{
List < int > list1 = Arrays.aslist(1,2,3,4,5);
show(list);
List <String> list2 = Arrays.aslist(“One”,”two”,”three”,”four”,”five”);
show(list2);
public static void show(List<?> list)
{
System.out.println(list);
}
}
}
What is the output of the program ?
CorrectIncorrect -
Question 4 of 15
4. Question
Which are the things used to decide the type of wildcard for the program ?
CorrectIncorrect -
Question 5 of 15
5. Question
Which of the following is the correct syntax of Unbounded wildcards in Java ?
CorrectIncorrect -
Question 6 of 15
6. Question
class Unbounded {
public static void main ( String args [ ] )
{
List<Object> array1 = new ArrayList(“Integer”,”String”,”Character”);
print(array1);
List<Object> array2 = new ArrayList(1 , 10 , 11 , 10 , 12 , 20 );
print(array2);
public static void print(List < ? > list)
{
System.out.println(list);
}
}
}
What is the output of the program ?
CorrectIncorrect -
Question 7 of 15
7. Question
Which of the following is not a correct syntax for using wildcards in java ?
CorrectIncorrect -
Question 8 of 15
8. Question
class Addition {
public static void main ( String args [ ] )
{
List < Integer > l1 = new ArrayList(10,8,6,4,2);
add(l1);
public static void add(List < ? extends Number > list)
{
int sum=0;
for( Number i : l1)
{
sum = sum+i;
}
system.out.println(sum);
}
}
What is the output of the program ?
CorrectIncorrect -
Question 9 of 15
9. Question
class LowerBound {
public static void main ( String args [ ] )
{
List<Integer> l1 = Arrays.aslist(10,20,30,40,50);
display(l1);
List <Number> l2 = Arrays.aslist(10.00,20.00,30.00,40.00,50.00);
public static void display(List<?super>list)
{
System.out.println(list);
}
}
}
What is the output of the program ?
CorrectIncorrect -
Question 10 of 15
10. Question
Super keyword is used in which of the following wildcards ?
CorrectIncorrect -
Question 11 of 15
11. Question
class Main {
public static void main ( String args [ ] )
{
List < Object > list1 = new Arraylist(“String”,1,’c’);
print(list1);
List<Integer> list2 = new ArrayList(2 , 3, 6 , 18 , 108 );
print(list2);
public static void print(List<?> list)
{
System.out.println(list);
}
}
}
What is the output of the program ?
CorrectIncorrect -
Question 12 of 15
12. Question
class Numbers {
public static void main ( String args [ ] )
{
List < Integer > l1 = new ArrayList(25 , 75 , 125 , 175 , 225 , 275 , 325);
add(l1);
public static void add(List < ? extends Number > list)
{
System.out.println(l1.size());
}
}
}
What is the output of the program ?
CorrectIncorrect -
Question 13 of 15
13. Question
Which variable can be an in variable in Java ?
CorrectIncorrect -
Question 14 of 15
14. Question
Which of the following is the correct syntax of Lower bound wildcards in Java ?
CorrectIncorrect -
Question 15 of 15
15. Question
class Main {
public static void main ( String args [ ] )
{
List<Integer> array1 = Array.mylist(10,100,1000,10000,100000);
message(array1);
List<Double> array2 = Array.mylist(1.1,1.11,1.111,1.1111,1.11111);
text(array2);
public static void text( List < ? super > list )
{
System.out.println(list);
}
}
}
What is the error in the program ?
CorrectIncorrect
Summary:
So you’ve taken the Java Wildcard Quiz and put your skills to the test! This quiz covered essential concepts like unbound, upper bound, and lower bound wildcards, along with their applications in generic code. By reviewing both your correct and incorrect answers, you can gain valuable insights into your strengths and weaknesses in this crucial domain.
Remember, effective learning is an ongoing process. Explore additional resources beyond the quiz to deepen your understanding. Consider online courses, tutorials, and practice problems to further solidify your grasp of wildcards in Java.