hw_24.swift

import UIKit

//================ # 1 ==================

let stringArray = ["Mr. Smith", "antony", "2", "cat Mr. Jons", "17", "other", "Mr.", "27", "home"]

func isInsertText(_ text: String) -> Bool {
    return text.contains("Mr.")
}

func isLess(_ text: String) -> Bool {
    return text.count <= 5
}

print("\n================ # 1 ==================\n")
print("\(stringArray.filter(isInsertText(_:)))")
print("\(stringArray.filter { $0.contains("Mr.")})")
print("\(stringArray.filter(isLess(_:)))")
print("\(stringArray.filter { $0.count <= 5 })")

//================ # 2 ==================

let numberArray = [2, 3, 4, 29,3, 17]
let numberMult = numberArray.reduce(1, { $0 * $1 })
let newString = stringArray.reduce("/ ", { $0 + $1 + " / " })

print("\n================ # 2 ==================\n")
print("\(numberArray) --> \(numberMult)")
print(newString)

//================ # 3 ==================

let newStringAppend = numberArray.map { String($0) + "$" }

print("\n================ # 3 ==================\n")
print(newStringAppend)

//================ # 4 ==================

let optionalStringArray = [nil, "Alex", "", nil, "Bob"]
let newIntArray = stringArray.flatMap { Int($0) }
let newStringArray = optionalStringArray.flatMap { $0 == "" ? nil : $0 }

print("\n================ # 4 ==================\n")
print(newIntArray)
print(newStringArray)