Re:“Swift will be open source later this year”
by alkonaut on Monday June 08, 2015 @05:32PM
(#9682603)
> If i dont specify a type for my variable i should be able to change my variable's value to whatever type i want.
You mean you want to assign a string to a variable and then re-assign it to something else entirely such as a number?
Just reassigning at all is dubious in my opinion, and seeing a reassignment with a completely different type would make me flip the table in review.
If you ever want a "catch all" variable you can then explicitly type it as a base type like "object", and assign what you want. But that should be very rare, so it's perfectly natural that type inference assigns a static type to the field.
The only time you get bad inference is if you have subtypes and the first assignment is too narrow, e.g
Apple GetApple() { ... }
var myFruit = GetApple(); // type is Apple
if (cond)
myFruit = GetOrange(); // can't assign orange
In this scenario you have to declare explicitly as Fruit. But again: this is rare, and all reassignment should be rare! Always have good reason before mutating anything.
You mean you want to assign a string to a variable and then re-assign it to something else entirely such as a number?
Just reassigning at all is dubious in my opinion, and seeing a reassignment with a completely different type would make me flip the table in review.
If you ever want a "catch all" variable you can then explicitly type it as a base type like "object", and assign what you want. But that should be very rare, so it's perfectly natural that type inference assigns a static type to the field.
The only time you get bad inference is if you have subtypes and the first assignment is too narrow, e.g
Apple GetApple() { ... } var myFruit = GetApple(); // type is Apple if (cond) myFruit = GetOrange(); // can't assign orange
In this scenario you have to declare explicitly as Fruit. But again: this is rare, and all reassignment should be rare! Always have good reason before mutating anything.