In what cases is it permissible to perform an insert operation in a Map that has not yet been initialized?

In Go, you cannot perform an insert operation into a map if it has not been initialized (i.e., is nil), as this will cause a runtime panic.

Initialization of a map is done using the make function:

m := make(map[string]int)
m["key"] = 42 // correct

If the map is nil, an attempt to write to it will cause a panic:

var m map[string]int
m["key"] = 42 // panic: assignment to entry in nil map

Exception:

• If the map is declared but not initialized, it can be initialized directly before insertion.
• Sometimes, a map may be initialized in a constructor or function and passed further.

Thus, inserting into an uninitialized map is only permissible after explicit initialization via make or assigning an already initialized map. Without this, the operation will cause a runtime error.