7.1 Introduction to ArrayList

• An ArrayList automatically resizes when elements are added or removed.


  True
• The size of an ArrayList is resizable
• What happens to the size of an ArrayList when you add or remove elements?

  It grows or shrinks
• ArrayLists require the use of wrapper classes for primitive data types.


  True
• What is one key benefit of using an ArrayList over a regular array in Java?

  Dynamically resizable
• What package must be imported to use ArrayList in Java?

  $java.util.ArrayList$
• The `remove()` method in an ArrayList shifts subsequent elements to the left.


  True
• Steps to iterate through an ArrayList using a regular `for` loop

  1️⃣ Initialize index variable

  2️⃣ Check loop condition (index < size())

  3️⃣ Retrieve element at current index

  4️⃣ Process the element

  5️⃣ Increment index variable
• An ArrayList is a dynamic, ordered collection of objects
• Match the feature with the corresponding data structure:

  Data Type | ArrayList ↔️ Objects only

  Size | ArrayList ↔️ Resizable

  Data Type | Array ↔️ Primitive and Objects

  Size | Array ↔️ Fixed
• What is the main advantage of using ArrayList over a regular array?

  Dynamic size
• ArrayLists can only store objects, requiring primitive types to be wrapped.
• What type of data can an ArrayList store?

  Objects only
• To use ArrayList in Java, you must import the java.util.ArrayList package.
• Order the steps to create and use an ArrayList:

  1️⃣ Import java.util.ArrayList

  2️⃣ Create an ArrayList object

  3️⃣ Add elements using add()

  4️⃣ Access elements using get()
• ArrayLists avoid the need to predefine a fixed size.

  True
• The size of an ArrayList is resizable, allowing it to adapt to changing data requirements.
• The dynamic size of ArrayLists avoids the need to predefine a fixed size.
• ArrayLists can store primitive data types directly without wrapping them into objects.

  False
• What does the `add()` method do in an ArrayList?

  Adds an element
• What does the `size()` method return in an ArrayList?

  Number of elements
• What is the main difference between an ArrayList and a regular array in terms of size?

  Resizable vs. fixed
• What type of data can an ArrayList store in Java?

  Objects only
• The main advantage of using an ArrayList over an array is its dynamic size
• What happens to the size of an ArrayList when new elements are added?

  It is dynamically resized
• Match the ArrayList method with its description:

  `add(element)` ↔️ Adds the element to the end

  `remove(index)` ↔️ Removes the element at index

  `get(index)` ↔️ Returns the element at index

  `size()` ↔️ Returns the number of elements
• When should you use an enhanced `for` loop instead of a regular `for` loop when iterating through an ArrayList?

  When no index is needed
• To handle a NullPointerException, you must ensure the ArrayList is initialized before use.


  True
• ArrayLists store only objects, while arrays can store primitives and objects.
• The size of an ArrayList is fixed once initialized.

  False
• What is the primary use case for an ArrayList when compared to an array?

  Managing data size
• What happens to subsequent elements in an ArrayList when an element is removed using `remove(index)`?

  They shift to the left
• An IndexOutOfBoundsException occurs when accessing an index outside the range of the ArrayList
• What is a key advantage of using ArrayList over regular arrays in terms of size?

  Dynamic resizing
• The size of an ArrayList is dynamically resizable
• ArrayLists are particularly useful when the size of the data is not known in advance
• The `get()` method returns the element at the specified index
• The enhanced `for` loop is more concise than a regular `for` loop for iterating through an ArrayList.


  True
• ArrayLists automatically resize when elements are added or removed, unlike arrays.

  True
• What import is required to use ArrayList in Java?

  `java.util.ArrayList`