Can we use slice as Map Keys in Go

Question: Can we use slice as map key in Go? Short answer is No

Do you want to know more? Okay, Let’s have a look at spec.

From Map spec:

The comparison operators == and != must be fully defined for operands of the key type; thus the key type must not be a function, map, or slice.

Map spec already tells us that slice can’t be a key, but we can also check it in the comparison spec:

Slice, map, and function values are not comparable.

This means slice can’t be a key in a map, but an array can be a key. For example we can write:

    testMap := map[[2]string]string{
        [2]string{"a", "b"} : "ab",
    }

There is our answer, slices can’t be key in Map, but an array can be.