Solving the "does not support indexing" error in a Go program

If you’re reading this post you’re probably searching on Google how to solve this problem: you’re passing a pointer to a slice or map in a function, and when referencing an item with *variable[0], you get that error.

How do I solve it?

The solution is simple: instead of using

*variable[0]

use

(*variable)[0]

Why am I getting this weird error? 🤔

*variable[0] is interpreted by the Go compiler as *(variable[0]). So what you’re telling the compiler to do is, get the first element in the slice, or the map item with key 0, and dereference that pointer.

This explains the error: variable in that context is a pointer, not a value, so you cannot get the [0] item of a pointer to an address, you need to dereference it first to get the value, which is what I think you are trying to do in the first place.