How to Handle 'Invalid Memory Address or Nil Pointer Dereference' Errors When Accessing Map Elements in Go?

"Map[string]*Type "Invalid Memory Address or Nil Pointer Dereference"

When accessing a structure's fields, you may encounter the error "invalid memory address or nil pointer dereference." This typically indicates that the pointer to the structure is either not initialized or pointing to an invalid memory address.

In your case, you're attempting to set a field in a condition map. However, because the condition map is an empty map of pointers, you retrieve a nil value for the *guardduty.Condition from condition.

According to "Maps in Action" for Go, you can test for the presence of a key using a two-value assignment:

i, ok := m["route"]

In this assignment, i is assigned the value stored under the "route" key. If the key does not exist, i is assigned the value type's zero value (0). The second value, ok, is a boolean that indicates whether the key exists in the map.

To resolve the issue, modify your code as follows:

if cond, ok := condition["id"]; !ok { // <nil> false
    log.Println("Pointer is null")
} else {
    // Initialize a new guardduty.Condition
    // and assign it to the required key
    nc := &guardduty.Condition{Equals: strPtr}
    condition["id"] = nc
}

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