What are reference types arrays?

Arrays of reference types are data structures that store not the objects themselves, but references to them in memory. Each element of the array is a pointer to the location of an object in the "heap".

Key features:

• Store references: Array elements store addresses of objects.
• Object creation: Objects referenced by the array are created separately using the new operator. The array itself is also created with new.
• Default value: For reference type array elements, the default value is null if no other value is assigned. This means the reference points "nowhere".
• Dynamic size: Although the array itself has a fixed size after creation, the objects it references can be dynamic (e.g., strings or lists).

Example in Java:

// Creating an array of reference type String
String[] names = new String[3];

// Assigning references to String objects
names[0] = new String("Alice");
names[1] = "Bob"; // String literals also create objects

// Default value for uninitialized elements
// names[2] is `null` by default

// Accessing objects via references
int lengthOfFirstName = names[0].length();