> Also, if the map has arrays as elements, it will magically create one, like Python's defaultdict.
Err, no Go doesn't do that. No insertion happens unless you explicitly assign to the key.
Err, no Go doesn't do that. No insertion happens unless you explicitly assign to the key.
my_map := make(map[int32][]int64)
val := my_map[123]
val = append(val, 456)
my_map[123] = val
fmt.Println(my_map)
I guess it's convenient compared to Rust's strict approach with entry API. But also, what I found is that golang's subscript returns nil in one case: if the value type is a nested map.
my_map := make(map[int32]map[int32]int64)
val := my_map[123]
val[456] = 789
my_map[123] = val
fmt.Println(my_map)
panic: assignment to entry in nil mapnil is equivalent to the empty array, which is why the rest of the code works as it does.
val, ok := my_map[123]
if ok {
...
}