What does a double question mark mean?

~/ Divide, returning an integer result . and ~/= integer division and assignment. There is not really an equivalent in Java. In Java the result is an integer if the result is assigned to an integer variable (not sure though, not a Java dev)

The operators are special symbols that are used to carry out certain operations on the operands . The Dart has numerous built-in operators which can be used to carry out different functions, for example, ‘+’ is used to add two operands. Operators are meant to carry operations on one or two operands.

The double question mark operator is called the nullish coalescing operator, and it’s a new feature of JavaScript ES2020 that allows you provide a default value to use when a variable expression evaluates to null or undefined .

“!” is a new dart operator for conversion from a nullable to a non-nullable type . Read here and here about sound null safety. Use it only if you are absolutely sure that the value will never be null and do not confuse it with the conditional property access operator. Follow this answer to receive notifications.

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.

If double question marks are uses it is to emphasise something in return, usually from the shock of the previous thing said . For example, if I said: ‘My dog just died’ (sad, but used for example…) Someone may reply.