Closures.md

Clousures

• Clousures are reference types
• Functions without a name
• Anonymous functions
• Ref to Map function
• Ref to Clousures
• More Details

Typical way of passing functions around

func calculator(n1: Int, n2: Int, operation: (Int, Int) -> Int) -> {
  return operation(n1, n2)
}

fun multiply(no1: Int, no2: Int) -> Int {
  return no1 * no2
}

calculator(n1: 2, n2: 3, operation: multiply)

Closure way

Example 1

func calculator(n1: Int, n2: Int, operation: (Int, Int) -> Int) -> {
  return operation(n1, n2)
}

let result = calculator(n1: 2, n2: 3) {$01 * $1})
print(result)

Example 2

// Add one to each element 
let array = [6, 2, 3, 9, 4, 1]

array.map({$0 + 1})

Closure Expression Syntax

Closure expression syntax has the following general form:

{ (parameters) -> return_type in
    statements
}