CODE EXAMPLE FOR SWIFT

Swift Nested Function with Return Values

func operate(symbol: String) -> (Int, Int) -> Int {

  // inner function to add two numbers 
  func add(num1:Int, num2:Int) -> Int {
    return num1 + num2
  }

  // inner function to subtract two numbers    
  func subtract(num1:Int, num2:Int) -> Int {
    return num1 - num2
  }

  let operation = (symbol == "+") ?  add : subtract
  return operation
}

let operation = operate(symbol: "+")
let result = operation(8, 3)
print("Result:", result)