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The Problem With 2D Arrays
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The Problem With 2D Arrays

2D arrays are a common topic that people want to know about. How can you make a 2D array in C#, Python, Java, Go—what is the syntax, how can you access elements? But for the most part the articles I have on 2D arrays ignores the main problems with 2D arrays.

Basically the best time to use a 2D array is never. It is usually better to just use one-dimensional arrays, nested arrays (which are like jagged arrays), or even hashtables. Often, data are sparse, and 2D arrays in most languages use memory for all elements—this wastes a lot of memory.

Here are some things I have found:

2D arrays end up having syntax that is complicated and hard to read.
Other data structures like nested arrays or hashtables are more memory-efficient (and faster).
For numerical processing, using third-party libraries is almost always a better solution than trying to do things directly with 2D arrays.

2D arrays, like recursive methods, are a feature that most programs would be better off not using. Other solutions are simpler and usually faster. I suppose, for completeness, learning about 2D arrays is worthwhile however.

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