Master Array Chunking in Go

Throughout my career, I've encountered array chunking in everything from pagination systems to batch processing jobs. What seems simple at first glance hides tricky edge cases that can silently corrupt your data—like out-of-bounds errors or inconsistent chunk sizes.

Today, I'm going to show you my battle-tested algorithm for chunking arrays in Go—one that handles all those edge cases cleanly.

Problem Statement

Write a function that takes an array and a chunk size as input. The function should return a new array where the original array is split into chunk of the specific size.

I like to start by breaking down the problem into three parts: input, process, and expected output. This way, I can identify the steps to go from A (the input) to B (the output).

Input: The array to be split and an integer that indicates the chunk size.

Output: An array of arrays.

With this identified, I can start with my solution. The expected array is formed by smaller arrays, where each one is a chunk from the original array with the specified size. Now, I can plan an algorithm to obtain these chunks.

Algorithm to Solve it

The first step for splitting the array into chunks is validating the size. My first code block is an if statement that checks whether the input is less than or equal to zero. If it is, I return nil since the array can't be split into chunks of zero length.

if size <= 0 {
        return nil
}

Next, I initialize a new array to hold the chunks.

var chunks [][]int

Then, I loop through the original array in increments of the chunk size. I start at index zero, and in each iteration, I increment my index by the chunk size value. For example, if the chunk size is 2, in the first iteration i = 0, in the second i = 2, in the third i = 4, and so on.

for i := 0; i < len(arr); i += size {}

For each iteration, I need to determine the end position of the chunk. My i variable marks where the chunk starts, so I use the min built-in function to find where it should end.

end := min(i+size, len(arr))

Finally, I append the chunks array with the portion of the original array, using a slice with my two variables i and end.

chunks = append(chunks, arr[i:end])

Once I've looped through the entire original array, I have all the chunks stored in the new array. I get my expected output—now I just need to return it.

return chunks

Final Thoughts

As you can see, my approach is simple but effective. I like to keep things simple—I prefer understanding the problem over chasing fancy solutions.

If you want to see the code for this and other algorithms, check out my GitHub repository: https://github.com/RubenOAlvarado/algorithms

Remember, this is my algorithm—you can define your own. Use this as a guide if you're stuck or have questions about the topic. After all, the best artists steal, and coding is an art.

What other chunking strategies have you used in production? Or better yet—try extending this to handle 2D arrays and share your solution on GitHub. Keep coding, and I'll see you in the next one.

Learn Array Chunking in Go: A Comprehensive Algorithm Approach

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Problem Statement

Algorithm to Solve it

Final Thoughts

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Comments

DSA with Go

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More from this blog

Problem Statement

Algorithm to Solve it

Final Thoughts