A look at Dart's null safety syntax

[alexeypetrushin]

A typing mistake, I meant the union types for for primitive types (at least for 
primitive types, ideally for any type).

Exhaustive Type Checking. Compile type checking for correct usage of union 
types in if/switch/return statements and functions.
    
    
    function makeDessert( fruit: 'banana' | 'orange' ): string {
      switch( fruit ) {
        case 'banana': return 'Banana Shake'
        case 'orange': return 'Orange Juice'
      }
      return fruit // Compiler will spot this as unreachable code.
    }
    
    
    Run