// funct1.swift
// By default, functions use their parameter names as labels for their
// arguments. Write a custom argument label before the parameter name,
// or write _ to use no argument label.

#if os(OSX) || os(iOS) // for libraries, portable for OSX and Linux
import Foundation
#elseif os(Linux)
import Glibc
#endif// 


print("funct1.swift running \n")
func greet(_ person: String, on day: String) -> String {
   return "Hello \(person), today is \(day)."
}

let ans = greet("John", on: "Wednesday")
print(ans)
print(" ")

// a function can take variable number of arguments
func arithmeticMean(_ numbers: Double...) -> Double {
  var total: Double = 0
  for number in numbers {
    total += number
  }
  return total / Double(numbers.count)
} // end arithmeticMean

var mean: Double = 0
mean = arithmeticMean(1, 2, 3, 4, 5)
// returns 3.0, which is the arithmetic mean of these five numbers
print("mean = \(mean)")

mean = arithmeticMean(3, 8.25, 18.75)
print("mean = \(mean)")


// a function can take a vector
func aMean(_ numbers: [Double]) -> Double {
  var total: Double = 0
  var count: Double = 0
  for number in numbers {
    total += number
    count += 1.0
  }
  return total / count
} // end aMean

let V = [1.0, 2.0, 3.0, 4.0, 5.0]
print("V = \(V)")
mean = aMean(V)
print("mean V = \(mean)")



var W = Array(repeating: 5.5, count: 4)
print(W)
mean = aMean(W)
print("mean W = \(mean)")
print("funct1.swift finished \n")