Arrays vs. Go Slices
Explore the differences between fixed-size Go arrays and dynamic slices. Understand their memory structure, type safety, and when to use each. Gain practical knowledge on implementing and choosing the right data structure for scalable and efficient Go code.
We'll cover the following...
At this point, the concept of arrays is clear, including what they are, how indexing works, how they are stored in memory, and how size and dimensions affect their structure. The next step is learning how to work with arrays in Go.
Go gives us two closely related tools for ordered data: built-in arrays and slices. In this lesson, we will explore both, understand what sets them apart, and learn when to use each.
The array type
As we already know, Go provides a built-in array type. An array in Go is a true typed array: it stores a fixed number of elements of one specific type. Once we declare an array as an int array, every element in it must be an integer. We cannot mix integers with strings, floats, or elements of any other data type in that same array. This is exactly what we meant when we described arrays as a collection of elements of the same type, stored in contiguous memory locations.
This homogeneous nature is not arbitrary. It is what allows the computer to store all elements directly in contiguous memory, calculate the address of any element instantly using the address formula, and process the data efficiently. Every slot in the array is guaranteed to be the same size, which is what makes all of this possible.
Implementation
Arrays are built into Go, so no special package is needed to create one. A Go file simply starts with a package declaration:
package main
Once we are writing Go code, we can create an array using the syntax [size]Type{...}. The size is part of the array's type, and the ...