A Golang Slice gotcha that...got me

Sat, 21 Feb 2026 12:33:28 -0800

I was doing some self study the other day, feeling relatively confident building out a Trie for an autocomplete function. When checking my work with Gemini, I was recommended something like this as a possible function signature:

func (t *Trie) collect(n *TrieNode, pfx string, results *[]string) {
 // ...
}

Where I started to spiral was the *[]string type in the final input parameter.

That’s weird looking, isn’t it?

In Golang, slices and arrays are often confused. You may say: “But aren’t slices copied by reference?”

Arrays on A Blog for the Uninitialized

A Golang Slice gotcha that...got me