Swift also introduces automatic type inference, which is in most cases pretty handy. I used this already in C# and it saved a lot of typing. But in C# it was only restricted to method scopes, means, you can only use this inside a method and you also need to assign a value directly.
In Swift you can also specify a concrete type, if you like to:
“let explicitDouble: Double = 70”
Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks. https://itun.es/de/jEUH0.l