Java Arrays Has Wonderful Opportunity-2025

Java Arrays

👉What is a Java Array?

An array in Java is a data structure that stores multiple values of the same data type in a single variable. Arrays allow efficient data management by grouping elements under a common name. The first element starts at index 0. Java arrays inherit from the Object class and implement Serializable and Cloneable interfaces. They can store both primitive data types and objects.

👉Why Use Java Arrays?

Instead of declaring multiple variables like

int x0 = 0;
int x1 = 1;
int x2 = 2;
int x3 = 3;

We can use an array:

int x[] = {0, 1, 2, 3};

This helps in easy looping and efficient memory usage:

for(int count = 0; count < x.length; count++) {
System.out.println(x[count]);
}

👉Types of Arrays in Java:-

1. Single-Dimensional Array – A simple array with elements in a single row.
2. Multidimensional Array – An array containing multiple arrays (like a matrix).

Declaring, Constructing, and Initializing Java Arrays:

1. Declaring an Array:

Syntax:

<dataType>[] <arrayName>;

<dataType> <arrayName>[];

Example:

int[] intArray;

2. Constructing an Array:

We allocate memory using new:

intArray = new int[5];

3. Initializing an Array:

intArray[0] = 10;
intArray[1] = 20;

Shorter way:

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

👉Java Array Example:-

class ArrayDemo {
public static void main(String args[]) {
int array[] = new int[5];
for (int count = 0; count < 5; count++) {
array[count] = count + 1;
}
for (int count = 0; count < 5; count++) {
System.out.println(“array[” + count + “] = ” + array[count]);
}
}
}

Output:

array[0] = 1
array[1] = 2
array[2] = 3
array[3] = 4
array[4] = 5

👉Java Array Length Property:-

System.out.println(“Length of Array = ” + array.length);

Output:

Length of Array = 5.

👉Java Array Index Out of Bounds Exception:-

Java checks array bounds and throws an exception if accessed beyond its size:

array[6] = 10; // Throws ArrayIndexOutOfBoundsException.

👉Java Arrays are Passed by Reference:-

Arrays in Java are passed by reference, meaning changes made inside a method affect the original array.

class ArrayDemo {
public static void passByReference(String a[]) {
a[0] = “Updated”;
}
public static void main(String args[]) {
String[] fruits = {“Apple”, “Mango”, “Orange”};
System.out.println(“Before Function Call: ” + fruits[0]);
passByReference(fruits);
System.out.println(“After Function Call: ” + fruits[0]);
}
}

Output:

Before Function Call: Apple.
After Function Call: Updated.

👉Multidimensional Arrays in Java:-

A multidimensional array is an array of arrays. It is commonly used for matrices or tables.

int[][] twoD = new int[3][3];
twoD[0][0] = 1;
twoD[1][1] = 2;
twoD[2][2] = 3;
System.out.println(twoD[0][0]);

Output:

1

👉Conclusion:-

• Java arrays allow you to store multiple elements of the same data type.
• They support both single-dimensional and multidimensional structures.
• Arrays are passed by reference, and Java performs boundary checks to prevent memory corruption.
• Knowing how to declare, initialize, and manipulate arrays effectively is crucial for Java programming.

Related Topics:

• ArrayList in Java.
• Difference Between Arrays and Collections.
• Sorting Arrays in Java.
• Searching Elements in an Array.

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