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’ .
What is double question mark in Dart?
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’ .