How to write complex C-style for statements in Swift 2.2

Question

How will I be able to implement a C-style for loop like this in Swift 2.2?

for var level: Double = 10; level <= 100; level += 10 {

}

Than loop over an int and create a double from it in the loop. — vikingosegundo, Mar 24 '16 at 16:30

score 5 · Answer 1 · edited May 23 '17 at 12:08

5

for level: Double in 10.stride(through: 100, by: 10) {
}

or in functional style:

(1...10).map { Double($0) * 10.0 }.forEach {
    print($0)
}

Please, don't use var for iterators and don't change the value of an iterator from inside the loop.

I give more examples in this answer

edited May 23 '17 at 12:08

Community

answered Mar 24 '16 at 08:57

Sulthan

Quite straightforward! – Oleg Gordiichuk Mar 24 '16 at 09:01
Thanks. I think old version is more readable, not sure if familiarity bias or not. Functional style isn't readable at all. – Esqarrouth Mar 24 '16 at 09:04
1

@Esq In this case, I wouldn't use the functional style but it's definitely the familiarity. For functional style it really helps to give a name (e.g. `let printIndex = {... }` and then `.forEach(printIndex)`) to every closure. – Sulthan Mar 24 '16 at 09:06

score 2 · Answer 2 · answered Mar 24 '16 at 09:02

2

For your specific example, what Sulthan said.

More generally, for truly complex ones, any C-style for loop:

for init; cond; step { statement }

can be converted to while:

init
while (cond) {
  statement
  step
}

answered Mar 24 '16 at 09:02

Amadan

2 Answers2