What are Null-aware operators?

Null-aware operators in Dart are a set of operators that allow you to safely handle null values in your code. They help you avoid runtime errors caused by null values and make your code more concise and readable. Here are the main null-aware operators in Dart:

1. The null-coalescing operator (??): This operator returns the value on its left side if it's not null, otherwise it returns the value on its right side. It's useful for providing a default value when a variable might be null[1][2][3].

Example:

String? username;
String defaultUsername = username ?? 'Guest';

2. The null-aware assignment operator (??=): This operator assigns a value to a variable only if the variable is currently null. If the variable is not null, it remains unchanged[2][3].

Example:

String? username;
username ??= 'Guest';

3. The null-aware access operator (?.): This operator allows you to safely access properties and methods of an object that might be null. If the object is null, it returns null i...