Hacker News Reader

Comment by mraleph | Hacker News Reader

In Dart 3 instead of declaring the variable and then comparing you can simply write an if-case pattern:

    if (value case final value?) {
      // value is a fresh final variable 
    }

So Dart is moving in the Swift direction, which has

    if let value = value {
      // a new binding named ‘value’ refers to value, unwrapped 
    }

or (newer syntax that I initially found even weirder than the older one, but both grew on me)

    if let value {
      // a new binding named ‘value’ refers to value, unwrapped 
    }

(The old version will remain, as it is more flexible, allowing such things as

    if let baz = foo.bar(42) {
      // a new binding named ‘baz’ refers to foo.bar(42), unwrapped 
    }
)

The more you know, I had totally missed this.