"Null-forgiving Operator"

public void PrintFieldLengthsIfNonNull() {
    if (_nullableField != null) PrintFieldLengths();
}

void PrintFieldLengths() {
    Console.WriteLine($"Non-nullable field length is: {_nonNullableField.Length}");
    
	// Null-forgiving operator (!) disables compiler warning here caused by accessing .Length property of potentially-null _nullableField without null check
	Console.WriteLine($"Nullable field length is: {_nullableField!.Length}");
}


Code snippet taken from "Complete C# Quick Reference - C# 8".