Anonymous Array in Java

Last Updated: 26 March, 2023

In Java, an anonymous array is an array that is created without explicitly assigning it to a variable. Instead, it is created directly as an argument to a method or as a value in an expression.

• The main purpose of an anonymous array is for instant and one-time usage only.
• The total number of elements passing inside {} will become the size of an anonymous array, so there is no need to mention the size of the anonymous array in [].

Syntax to create single-dimensional anonymous array
new <data type>[] { <list of values with comma separator> };

Syntax to create multidimensional anonymous array
new <data type>[][] { {<list of values with comma separator>},
{<list of values with comma separator>} };

Example: Anonymous Int Array

new int[] { 10, 20, 20, 40, 50};

Example: Anonymous char Array

new char[] { 'J', 'A', 'V', 'A' };

Example: Anonymous String Array

new String[] { "MySQL", "Oracle", "MongoDB", "Cassandra" };

Example: Anonymous Multidimensional Array

new int[][] { {2, 4, 6, 8}, {5, 10, 15, 20} };

Anonymous arrays are useful when we need to create an array with a few elements and don't need to reuse the array later in the code. It can also be used to make the code more concise and readable by avoiding the need to assign a name to the array.

Let's understand an anonymous array with the help of given examples:

Example 1 : Single Dimensional Anonymous Array in Java

public class AnonymousArrayExample1 { public static void main(String[] args) { // Passing an Anonymous array to a method printArray(new char[] {'J', 'A', 'V', 'A'}); } // Method to print array elements static void printArray(char[] ch) { for (int i = 0; i < ch.length; i++) { System.out.print(ch[i] + "\t"); } } }

Output

J A V A

Example 1 : Multidimensional Anonymous Array in Java

public class AnonymousArrayExample2 { public static void main(String[] args) { // Passing an Anonymous array to a method printArray(new int[][] { { 2, 4, 6, 8 }, { 3, 6, 9, 2 }, {4, 8, 1, 4} }); } // Method to print array elements static void printArray(int[][] num) { for (int i = 0; i < num.length; ++i) { for (int j = 0; j < num[i].length; ++j) System.out.print(num[i][j] + "\t"); System.out.println(); // New Line } } }

Output

2 4 6 8
3 6 9 2
4 8 1 4