Arrays in Java

What is Array?

Arrays in Java allow for the storage of elements of the same type in a fixed-size sequential collection, with each element allocated a unique index number indicating its position within the array. They allow the grouping of several items of the same type.

Types of Java Arrays

In Java, arrays are classified into two types:

1. Single-dimensional array in Java.
2. Multidimensional arrays in Java

Single-Dimensional Array

A single-dimensional array in Java is a list of elements or components of the same type of value, identified by index values, and representing either a row or a column of array elements with the same name. These arrays can be identified by their respective index values.

Multidimensional arrays

In Java, multidimensional arrays can be two or three dimensions, generating arrays of arrays where each element is an array, allowing values to be stored in a tabular form similar to a row-column matrix.

Declare and Initialize an Array in Java

To declare and initialize an array in Java, give its data type, followed by square brackets holding the required size or the elements it will hold.

Array Operations

Array Operations includes

• Traversal.
• Insertion.
• Deletion.
• Search.
• Update.
• Sorting.
• Merging.
• Order statistics.

Advantages of Arrays

• Efficient access to Elements.
• Fast Data Retrieval.
• Versatility.
• Compatibility with hardware.

Disadvantages of Arrays

• An array can only contain the same type of element.
• It's really difficult to remove and add items.

Array Usages

• Stores variables with the same type.
• Solve matrix problems.
• Implements sorting algorithms.
• Implements database records.
• Enables CPU scheduling.
• Used to implement data structures such as stacks, queues, heaps, and hash tables.

What is an Array Class?

The Arrays class in the java.util package of the Java Collection Framework provides static methods for dynamically creating and accessing Java arrays. It consists only of static methods and those inherited from the Object class.

Accessing Elements of Array in Java

There are three types of accessing elements:

1. Direct access to an element.
2. Using a loop to access elements.
3. Accessing elements with a for-each loop.

1. Direct access to an element

This access method allows the user to directly access an array's exact element using an index number.

2. Using a loop to access elements

This access method allows you to access any specific array using iteration statements like a for loop. 

3. Accessing elements with a for-each loop

In this way, the for-each loop can be used to access the elements of the array.

Assigning Array Reference to Another Array

An array can assign an existing array and serve as a reference type of variable.

Array Literal 

Array literals can be utilized in cases when the array's size and variables are known. 

Anonymous Array in Java

Java has the anonymous array feature, which eliminates the requirement to declare the array when giving it to a function.