Breaking an array into smaller chunks in Java

05 Oct 2023

In many programming tasks, there is a need to break a large array into smaller, more manageable chunks. This can be useful when dealing with large datasets or when performing parallel operations on an array. In this article, we will explore different techniques to break an array into smaller chunks in Java.

Using Looping Constructs
Using Apache Commons Lang

Using Looping Constructs

One simple way to break an array into smaller chunks is by using looping constructs, such as for or while loops. We can iterate over the input array and create new smaller arrays within each iteration. Here’s an example:

public static ArrayList<int[]> breakArray(int[] arr, int chunkSize) {
    ArrayList<int[]> result = new ArrayList<>();
    int startIndex = 0;
    while (startIndex < arr.length) {
        int endIndex = Math.min(startIndex + chunkSize, arr.length);
        int[] chunk = Arrays.copyOfRange(arr, startIndex, endIndex);
        result.add(chunk);
        startIndex += chunkSize;
    }
    return result;
}

public static void main(String[] args) {
    int[] array = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    int chunkSize = 3;
    ArrayList<int[]> chunks = breakArray(array, chunkSize);
    for (int[] chunk : chunks) {
        System.out.println(Arrays.toString(chunk));
    }
}

In the above example, the breakArray method takes the input array and the chunk size as parameters. It creates a new ArrayList to store the smaller chunks and uses a while loop to iterate over the array. Within each iteration, it uses Arrays.copyOfRange to create a new chunk and adds it to the result list.

The main method demonstrates how to use the breakArray method, passing in an example array [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] and a chunk size of 3. The resulting chunks are then printed to the console.

Using Apache Commons Lang

Another approach to break an array into smaller chunks is by using the ArrayUtils class from the Apache Commons Lang library. This library provides various utility methods for manipulating arrays. Here’s an example of using ArrayUtils to break an array into chunks:

import org.apache.commons.lang3.ArrayUtils;

public static Object[][] breakArray(Object[] arr, int chunkSize) {
    return ArrayUtils.partition(arr, chunkSize);
}

public static void main(String[] args) {
    String[] array = {"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"};
    int chunkSize = 4;
    Object[][] chunks = breakArray(array, chunkSize);
    for (Object[] chunk : chunks) {
        System.out.println(Arrays.toString(chunk));
    }
}

In the above example, we import the ArrayUtils class from the Apache Commons Lang library. The breakArray method takes the input array and the chunk size as parameters. It uses the ArrayUtils.partition method to partition the array into smaller chunks and returns a 2D array.

The main method demonstrates how to use the breakArray method, passing in an example array ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"] and a chunk size of 4. The resulting chunks are then printed to the console.

Conclusion

Breaking an array into smaller chunks can help in scenarios where we need to process or analyze large datasets efficiently. In this article, we explored two different approaches to achieve this in Java – using looping constructs and using the Apache Commons Lang library. Choose the method that suits your needs and make your array manipulation tasks more manageable.

#java #array #chunking

Table of Contents

Using Looping Constructs

Using Apache Commons Lang

Conclusion