Swift Language Function as first class citizens in Swift Assigning function to a variable
Example
struct Mathematics
{
internal func performOperation(inputArray: [Int], operation: (Int)-> Int)-> [Int]
{
var processedArray = [Int]()
for item in inputArray
{
processedArray.append(operation(item))
}
return processedArray
}
internal func performComplexOperation(valueOne: Int)-> ((Int)-> Int)
{
return
({
return valueOne + $0
})
}
}
let arrayToBeProcessed = [1,3,5,7,9,11,8,6,4,2,100]
let math = Mathematics()
func add2(item: Int)-> Int
{
return (item + 2)
}
// assigning the function to a variable and then passing it to a function as param
let add2ToMe = add2
print(math.performOperation(inputArray: arrayToBeProcessed, operation: add2ToMe))
Output:
[3, 5, 7, 9, 11, 13, 10, 8, 6, 4, 102]
Similarly the above could be achieved using a closure
// assigning the closure to a variable and then passing it to a function as param
let add2 = {(item: Int)-> Int in return item + 2}
print(math.performOperation(inputArray: arrayToBeProcessed, operation: add2))
