How to Create an Array in Java?

Last Updated : 16 Jan 2026

In Java, an array is an object. It is a collection or group of similar data types. Elements of an array are stored in a contiguous memory location. An array in Java is index-based; the first element of the array is stored at the 0^th index, 2^ndelement is stored at the 1^st index and so on.

Creating an Array in Java

We can create an array by following the steps given below:

Declaration: First, specify the data type of the elements you want to store in an array, followed by a pair of square brackets and the array's name.

int[] empID; // Declares an integer array named 'empID'
String[] fruits; // Declares a String array named 'fruits'

Allocation: As we know, an array is an object in Java. So, we will use the new keyword to allocate memory for the array. It specifies the size of the array (number of elements that an array will hold). The size of the array is specified within square brackets.

empID = new int[6]; // Allocates memory for 6 integers
fruits = new String[6]; // Allocates memory for 6 Strings

Initialization (Optional): Initialization of an array at the time of declaration is optional. We can initialize it later.

Initialization at Declaration Time:Enclose the array elements within curly braces {}, separated by commas.

int[] empID = {121, 223, 301, 431, 501, 612};
String[] fruits = {"Mango", "Papaya", "Oranges", "Banana", "Pineapple", "Plum"};

Combined Declaration, Allocation, and Initialization

We can declare, allocate, and initialize an array in a single statement.

int[] empID = new int[]{121, 223, 301, 431, 501, 612};
String[] fruits = new String[] {"Mango", "Papaya", "Oranges", "Banana", "Pineapple", "Plum"};

1. Array Declaration and Allocation

One of the successions used to declare the array is by using the keyword new. It instructs Java to allocate memory for the declared array.

Example

public class Main {  
    public static void main(String[] args) {  
//array declaration and allocation
        int[] numbers = new int[5];   
        // array initialization
        numbers[0] = 10;  
        numbers[1] = 20;  
        numbers[2] = 30;  
        numbers[3] = 40;  
        numbers[4] = 50;  
        // Accessing array elements  
        for (int i = 0; i < numbers.length; i++) {  
            System.out.println("Element at index " + i + ": " + numbers[i]);  
        }  
    }  
}   

Compile and Run

Output:

Element at index 0: 10
Element at index 1: 20
Element at index 2: 30
Element at index 3: 40
Element at index 4: 50

2. Array Initialization

We can also initialize an array directly with values when declaring it, bypassing the need for assigning values individually.

Example

public class Main {  
    public static void main(String[] args) {  
        String[] fruits = {"Apple", "Banana", "Orange", "Grapes"};  
        // Accessing array elements  
        for (int i = 0; i < fruits.length; i++) {  
            System.out.println("Fruit at index " + i + ": " + fruits[i]);  
        }  
    }  
}

Compile and Run

Output:

Fruit at index 0: Apple
Fruit at index 1: Banana
Fruit at index 2: Orange
Fruit at index 3: Grapes

3. Creating Multidimensional (Two-Dimensional) Arrays

Multi-dimensional arrays in Java are basically arrays of arrays. It allows us to store data in a tabular or grid-like structure, making it useful for scenarios like matrices, game boards, or any data that requires multiple dimensions. It is useful when we want to store data in tabular form (rows and columns).

Declaration

We can declare and initialize a two-dimensional array in a single statement as follows.

Assigning Values

Examples

// 2D Array with two rows and two columns, initialized and assigned  
int[][] arr = { { 1, 2 }, { 3, 4 } };  
//array with three rows and three columns  
 int[][] arr = new int[3][3];  

Example of a Two-Dimensional Array

Example

public class Main {  
    public static void main(String[] args) {  
        int[][] matrix = {  
            {1, 2, 3},  
            {4, 5, 6},  
            {7, 8, 9}  
        };  
        for (int i = 0; i < matrix.length; i++) {  
            for (int j = 0; j < matrix[i].length; j++) {  
                System.out.print(matrix[i][j] + " ");  
            }  
            System.out.println(); // New line after each row  
        }  
    }  
}     

Compile and Run

Output:

1 2 3
4 5 6
7 8 9

4. Using Arrays.fill() Method for Initialization

Java provides a utility class named Arrays that contains a number of methods for array operations. The Arrays.fill() method provides the facility to set an initial value for an array equal to its size.

Example

import java.util.*;  
public class Main {  
    public static void main(String[] args) {  
        int[] numbers = new int[5];  
        // Filling the array with a specific value  
        Arrays.fill(numbers, 42); // All elements will be set to 42  
        // Printing the array  
        for (int i = 0; i < numbers.length; i++) {  
            System.out.println("Element at index " + i + ": " + numbers[i]);  
        }  
    }  
}     

Compile and Run

Output:

Element at index 0: 42
Element at index 1: 42
Element at index 2: 42
Element at index 3: 42
Element at index 4: 42

5. Creating Jagged Arrays (Arrays of Arrays)

A jagged array is a collection of arrays where each row may contain a variable number of elements. Jagged arrays are also known as "ragged arrays" or "irregular arrays". They can be created by specifying the size of each array in the declaration. For example, a jagged array with three rows can have the first row with three elements, the second with two elements, and the third with four elements.

To read more Jagged Array in Java

Example

public class Main {  
    public static void main(String[] args) {  
        // Creating a jagged array  
        int[][] jaggedArray = new int[3][];  
        jaggedArray[0] = new int[2];   
        jaggedArray[1] = new int[3]; // Second row has 3 columns  
        jaggedArray[2] = new int[4]; // Third row has 4 columns  
        // Initializing the jagged array  
        int value = 1;  
        for (int r = 0; r < jaggedArray.length; r++) {  
            for (int k = 0; k < jaggedArray[r].length; k++) {  
                jaggedArray[r][k] = value++;  
            }  
        }  
        // Printing the jagged array  
        for (int i = 0; i < jaggedArray.length; i++) {  
            for (int j = 0; j < jaggedArray[i].length; j++) {  
                System.out.print(jaggedArray[i][j] + " ");  
            }  
            System.out.println();  
        }  
    }  
}     

Compile and Run

Output:

1 2
3 4 5
6 7 8 9

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