Create unwrapping-multiple-optionals-in-flutter-and-dart.dart

tipsandtricks/unwrapping-multiple-optionals-in-flutter-and-dart/unwrapping-multiple-optionals-in-flutter-and-dart.dart

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+
+void main(List<String> args) {
+  /// unwrapping multiple optionals
+  print(getFullName(null, null)); // Empty
+  print(getFullName('John', null)); // Empty
+  print(getFullName(null, 'Doe')); // Empty
+  print(getFullName('John', 'Doe')); // John Doe
+}
+
+String getFullName(
+  String? firstName,
+  String? lastName,
+) =>
+    withAll([
+      firstName,
+      lastName,
+    ], (names) => names.join(' ')) ??
+    'Empty';
+
+T? withAll<T>(
+  List<T?> optionals,
+  T Function(List<T>) callback,
+) =>
+    optionals.any((e) => e == null) ? null : callback(optionals.cast<T>());