Calling instance method on each object in array

Question

Let's assume this situation: I have an array of objects and I want call instance method on each one of them. I can do something like that:

//items is an array of objects with instanceMethod() available items.forEach { $0.instanceMethod() } 

The same situation is with map. For example I want to map each object to something else with mappingInstanceMethod which returns value:

let mappedItems = items.map { $0.mappingInstanceMethod() } 

Is there a cleaner way to do that?

For example in Java one can do:

items.forEach(Item::instanceMethod); 

instead of

items.forEach((item) -> { item.instanceMethod(); }); 

Is similiar syntax available in Swift?

Answer 1

What you are doing in

items.forEach { $0.instanceMethod() } let mappedItems = items.map { $0.mappingInstanceMethod() } 

is a clean and Swifty way. As explained in Is there a way to reference instance function when calling SequenceType.forEach?, the first statement cannot be reduced to

items.forEach(Item.instanceMethod) 

There is one exception though: It works with init methods which take a single argument. Example:

let ints = [1, 2, 3] let strings = ints.map(String.init) print(strings) // ["1", "2", "3"] 

Answer 2

    for item in items {         item.instanceMethod()     }