Java ☕ Arrays and Array Lists

The video tutorial introduces arrays and ArrayLists in Java, explaining their differences and uses. It covers how to declare, access, and modify arrays, and introduces ArrayLists as a more flexible alternative. The tutorial includes exercises to practice using arrays and ArrayLists, demonstrating how to print specific elements and record data over time. Key concepts include data storage, array indexing, and ArrayList methods.

What is the starting index of an array in Java?

• 2

• 0

• 1

• 3

How do you declare an array in Java?

• int[] myArray = {1, 2, 3};

• int myArray = [1, 2, 3];

• array int myArray = {1, 2, 3};

• int myArray[] = (1, 2, 3);

What is a key limitation of arrays in Java?

• They are not supported in Java.

• They can only store integers.

• They cannot be resized after creation.

• They can only store strings.

Which method is used to add an element to an ArrayList?

• .push()

• .append()

• .add()

• .insert()

What is the purpose of a wrapper class in Java?

• To provide additional methods for primitive types.

• To convert strings to integers.

• To store multiple data types in one variable.

• To enhance the performance of arrays.

In the array exercise, what condition is checked to print ages?

• Ages less than 18

• Ages not equal to 18

• Ages equal to 18

• Ages greater than 18

How often are temperatures recorded in the ArrayList exercise?

• Every 10 seconds

• Every 5 seconds

• Every 20 seconds

• Every 15 seconds

What is the final temperature of heater 1 in the ArrayList exercise?

• 40.00 degrees Celsius

• 35.00 degrees Celsius

• 37.66 degrees Celsius

• 32.37 degrees Celsius

Which method is used to remove all elements from an ArrayList?

• .deleteAll()

• .clear()

• .removeAll()

• .empty()

What is the main advantage of using ArrayLists over arrays?

• They are faster.

• They have a dynamic size.

• They use less memory.

• They can store more data types.