All Flashcards
Why are ArrayLists more versatile than arrays?
ArrayLists are dynamic in size, allowing addition and removal of elements.
What is the purpose of the size() method in ArrayLists?
Returns the number of elements currently in the ArrayList.
Why must ArrayLists store objects instead of primitive types?
ArrayLists are designed to hold objects; primitive types must be wrapped in their corresponding class.
What is the significance of the import java.util.ArrayList; statement?
It makes the ArrayList class available for use in your Java code.
Explain the concept of traversing an ArrayList.
Iterating through each element of the ArrayList to perform an operation.
What is the purpose of searching in an ArrayList?
To find a specific element within the ArrayList.
What is the purpose of sorting an ArrayList?
To arrange the elements of the ArrayList in a specific order.
What is the ethical consideration when collecting user data?
Protecting user privacy and using data responsibly.
What does it mean for an ArrayList to be 'dynamic'?
Its size can change during runtime; elements can be added or removed.
Why is transparency important regarding data collection?
Builds trust with users and allows them to make informed decisions.
How is ArrayList used in real-world scenarios?
Storing a list of customers in a database or managing a playlist of songs.
How is linear search applied in real-world scenarios?
Finding a specific product in a small inventory list.
How is selection sort applied in real-world scenarios?
Sorting a small list of student names alphabetically.
How is insertion sort applied in real-world scenarios?
Sorting a hand of cards as you receive them in a card game.
How is encryption used to protect user data?
Securing online transactions and protecting sensitive information from hackers.
Give a real-world example of ethical data collection.
A research study that obtains informed consent from participants before collecting their data.
How are ArrayLists used in social media applications?
Storing lists of friends, posts, or comments.
How are ArrayLists used in e-commerce applications?
Managing shopping carts and product lists.
How is data collection used in healthcare?
Tracking patient health records and monitoring disease outbreaks.
How is data collection used in education?
Tracking student performance and personalizing learning experiences.
What does the following code output?
java
ArrayList<String> list = new ArrayList<>();
list.add("apple");
list.add("banana");
System.out.println(list.size());
2
What does the following code output?
java
ArrayList<Integer> list = new ArrayList<>();
list.add(10);
list.add(20);
list.set(0, 15);
System.out.println(list.get(0));
15
Identify the error in the following code:
java
ArrayList<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
System.out.println(list.get(2));
IndexOutOfBoundsException: The index 2 is out of bounds for the list of size 2.
What does the following code output?
java
ArrayList<String> list = new ArrayList<>();
list.add("A");
list.add("B");
list.remove(0);
System.out.println(list.size());
1
What does the following code output?
java
ArrayList<Integer> list = new ArrayList<>();
list.add(5);
list.add(10);
list.add(5);
int index = list.indexOf(5);
System.out.println(index);
0
What does the following code output?
java
ArrayList<String> list = new ArrayList<>();
System.out.println(list.size());
0
Identify the error in the following code:
java
ArrayList<int> list = new ArrayList<>();
ArrayLists cannot store primitive types directly. Use the Integer wrapper class instead: ArrayList
What does the following code output?
java
ArrayList<Integer> list = new ArrayList<>();
list.add(1);
list.add(2);
list.add(3);
list.clear();
System.out.println(list.size());
0
What does the following code output?
java
ArrayList<String> list = new ArrayList<>();
list.add("apple");
list.add("banana");
System.out.println(list.get(1));
banana
What does the following code output?
java
ArrayList<Integer> list = new ArrayList<>();
list.add(5);
list.add(10);
list.remove(Integer.valueOf(5));
System.out.println(list.size());
1