double question mark operator means “if null “. Take the following expression, for example. String a = b ?? ‘hello’; This means a equals b , but if b is null then a equals ‘hello’ .
Read moreHow do you use global variables in darts?
Show activity on this post. Just create a library file and create fields for globals you need there. Import this library everywhere you need access to these fields. create a singleton in the globals library (see How do you build a Singleton in Dart? for more details).
Read moreHow do you know what variable you are in Dart?
Dart objects have runtimeType property which returns Type . To check whether the object has a certain type, use == operator . Unlike is , it will only return true if compared to an exectly same type, which means comparing it with its super class will return false .
Read moreCan be null Dart?
The Dart language now supports sound null safety ! When you opt into null safety, types in your code are non-nullable by default, meaning that variables can’t contain null unless you say they can. With null safety, your runtime null-dereference errors turn into edit-time analysis errors.
Read moreWhat is string interpolation in Dart?
String interpolation is the process of inserting variable values into placeholders in a string literal . To concatenate strings in Dart, we can utilize string interpolation. We use the ${} symbol to implement string interpolation in your code.
Read moreWhat is null safety in flutter?
Null Safety in simple words means a variable cannot contain a ‘null’ value unless you initialized with null to that variable . With null safety, all the runtime null-dereference errors will now be shown in compile time.
Read moreWHAT IS null check operator in Dart?
Null-aware operators are used in almost every programming language to check whether the given variable value is Null . The keyword for Null in the programming language Dart is null. Null means a variable which has no values assign ever and the variable is initialized with nothing like.
Read more