How can I create an array of arrays in Java?

General Discussions
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1

I have five String[] arrays, and I want to store them inside another array. How do I achieve this?

Can I create a java array of arrays to hold them, and if so, what’s the correct syntax?

2

The easiest way to store multiple String [ ] arrays inside another array is by using a 2D array:

public class ArrayOfArrays {
    public static void main(String[] args) {
        String[] arr1 = {"A", "B"};
        String[] arr2 = {"C", "D"};
        String[] arr3 = {"E", "F"};
        String[] arr4 = {"G", "H"};
        String[] arr5 = {"I", "J"};

        String[][] arrayOfArrays = {arr1, arr2, arr3, arr4, arr5};

        // Accessing elements
        System.out.println(arrayOfArrays[2][1]); // Output: F
    }
}
3

If you need dynamic resizing, use an ArrayList<String [ ]> instead of a fixed-size array:

import java.util.*;

public class ArrayOfArrays {
    public static void main(String[] args) {
        List<String[]> listOfArrays = new ArrayList<>();
        listOfArrays.add(new String[]{"A", "B"});
        listOfArrays.add(new String[]{"C", "D"});
        listOfArrays.add(new String[]{"E", "F"});

        // Accessing elements
        System.out.println(listOfArrays.get(1)[0]); // Output: C
    }
}
  • Allows adding/removing arrays dynamically.
4

If the arrays store different data types, use an Object[][]:

public class ArrayOfArrays {
    public static void main(String[] args) {
        Object[][] mixedArray = {
            {"A", "B"},
            {1, 2},
            {3.5, 4.8}
        };

        // Accessing elements
        System.out.println(mixedArray[1][1]); // Output: 2
    }
}

It supports different data types in the same structure.