DartNull-aware Operators trong Dart
🎯 Mục tiêu: Operators để xử lý null values.
💡 Các operators
String? name;
// ?. - null-aware access
print(name?.length); // null (không crash)
// ?? - null coalescing
var displayName = name ?? "Guest";
// ??= - null-aware assignment
name ??= "Default";
// ! - null assertion
String notNull = name!; // Throws nếu null📝 Chaining
var user = getUser();
var city = user?.address?.city ?? "Unknown";🔧 ?[]
var list = [1, 2, 3];
List<int>? nullableList;
print(list[0]); // 1
print(nullableList?[0]); // null✅ Checklist
-
?.safe access -
??default value -
??=assign if null - Avoid
!when possible
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