Arrays

Arrays are fixed-size containers that store multiple values of the same type.

Creating Arrays

// Declaration
int[] numbers;

// Initialization with size
numbers = new int[5];

// Declaration and initialization combined
int[] scores = new int[10];

// Declaration, creation and initialization with values
String[] names = {"John", "Alice", "Bob"};

Accessing Elements

Array elements are accessed using zero-based indexing:

int[] numbers = {10, 20, 30, 40, 50};

// Accessing elements
int firstNumber = numbers[0];  // 10
int thirdNumber = numbers[2];  // 30

// Modifying elements
numbers[1] = 25;  // Changes 20 to 25

Array Length

The length property gives the size of an array:

int[] scores = new int[8];
System.out.println(scores.length);  // 8

String[] names = {"John", "Alice", "Bob"};
System.out.println(names.length);  // 3

Iterating

// Using for loop
int[] numbers = {1, 2, 3, 4, 5};
for (int i = 0; i < numbers.length; i++) {
  System.out.println(numbers[i]);
}

Common Pitfalls

• Array Index Out of Bounds: Accessing an index outside the array’s valid range
• NullPointerException: Using an array reference that hasn’t been initialized
• Fixed Size: Arrays cannot be resized after creation (use ArrayList for resizable collections)