Im attempting to make something similar to the high low game. So far i can get a new integer between 1-25 to be generated.
Ive tried to write a function that when you press the 'lower' button it checks the new integer against the previous one, and if it is less then text is displayed below saying 'You Were Correct' and updates the users score +1.. and if wrong 'You Were Wrong' displays instead and score is reset to 0.
Whenever i press the lower button it gives me a new int but score is not updated and the message doesn't display. This is my first real attempt at making this so bear with me :)
Lower Button
#IBAction func lower(sender: AnyObject) {
var newNumber = randomIntBetween(2, high: 26)
var oldNumber: Int?
func lowerNumber() -> Int {
if newNumber <= oldNumber {
correctWrong.text = "You Were Correct!"
score.text = "Score: \(countWin++)"
} else {
correctWrong.text = "You Were Wrong!"
score.text = "Score: \(countLose)"
}
return newNumber
}
randomNumbers.text = "\(newNumber)"
}
Random Number Function
func randomIntBetween(low:Int, high:Int) -> Int {
let range = high - (low - 1)
return (Int(arc4random()) % range) + (low - 1)
}
Variables/Constants Used
var countWin = 0
let countLose = 0
Thanks
As far I can see if your code it's formatted correctly you have a nested function but you aren't calling it inside your function so it's impossible that the function lowerNumber() will be called. You need to call the function like the following code:
#IBAction func lower(sender: AnyObject) {
var newNumber = randomIntBetween(2, high: 26)
var oldNumber: Int?
func lowerNumber() -> Int {
if newNumber <= oldNumber {
correctWrong.text = "You Were Correct!"
score.text = "Score: \(countWin++)"
} else {
correctWrong.text = "You Were Wrong!"
score.text = "Score: \(countLose)"
}
return newNumber
}
let newValue = lowerNumber()
randomNumbers.text = "\(newValue)"
}
Nevertheless, nested functions are closures that have a name and can capture values from their enclosing function so you need to be carefully with its use. I recommend this article of #AirSpeedVelocity to learn more about the closures and its capture values A Basic Tutorial on Functions and Closures in Swift
I hope this help you.
Related
If I want to evaluate time performance of a few algos using Date() or Dispatch() how can I create a function that does this?
For example this binary search algo. How can I pass it as a closure parameter and have the closure do all of the time performance measuring using any of the Swift time keeping methods below? Please answer with an example of a closure. Thanks.
let startingPoint = Date()
let startingPoint = Dispatch().now
func binarySearchForValue(searchValue: Int, array: [Int]) -> Bool {
var leftIndex = 0
var rightIndex = array.count - 1
while leftIndex <= rightIndex {
let middleIndex = (leftIndex + rightIndex) / 2
let middleValue = array[middleIndex]
if middleValue == searchValue {
return true
}
if searchValue < middleValue {
rightIndex = middleIndex - 1
}
if searchValue > middleValue {
leftIndex = middleIndex + 1
}
}
return false
}
Since you may want to measure different functions, it probably makes sense to capture the arguments for the function in the closure instead of including their types in the signature. But I did use a generic type for the return value. I hope that this is what you're after:
func measure<R>(_ label: String, operation: () -> R) -> R {
let start = DispatchTime.now()
let result = operation()
let end = DispatchTime.now()
let nanoTime = end.uptimeNanoseconds - start.uptimeNanoseconds
let timeInterval = Double(nanoTime) / 1_000_000_000
print(String(format: "%#: %.9f s", label, timeInterval))
return result
}
Here's how you use it:
let result = measure("search") { binarySearchForValue(searchValue: 3, array: [1, 3, 8]) }
print(result) // that's the result of the function that was measured, not the measurement
measure("some function") { functionWithoutReturnValue() }
If the function has no return value, R will be (), so that should work too. Just don't assign the result to anything (see the example above). If you want to do something with the measurement other than printing it to the console, you can do that, too. But you didn't specify that in your question, so I went with print.
Not sure what exactly you are after here and this solution below will only fit one specific function signature to test
func testBench(search: Int, array: [Int], testCase test: (Int, [Int]) -> Bool) {
let start = DispatchTime.now()
test(search, array)
let end = DispatchTime.now()
print("\(start) - \(end)")
}
called like this
testBench(search: 3, array: [6,7,5,3]) {binarySearchForValue(searchValue: $0, array: $1)}
You should use XCTest to measure the performance ... It gives you proper stats for your method in terms of performance
i.e.
func testMyCodesPerformance() {
measureBlock {
someClass.doSomethingFancy()
}
}
You can do lot more using XCTest measureBlock for performance testing
I can't find a way to implement a wait function, I'm using swiftforwindows and no examples online have been able to solve it so far. It's Swift 4.2
The class is basically an array that when a function is called each index on the array gets a constant value deducted. the tick function is what is being called. I'm new to Swift.
class resProj {
var list = [1,1,1,1]
var projReq = [100,200,300,50]
var completed = false
func tick(){
for count in 0..<projReq.count{
if projReq[count] <= list[count]{
projReq[count] = 0
}
else if projReq[count] > list[count]{
projReq[count] -= list[count]
}
}
print(projReq)
}
init(
mathsP mathsIn: Int,
scienceP sciecnceIn: Int,
enginerP enginerIn: Int,
businessP businessIn: Int) {
self.list [0] = mathsIn
self.list [1] = sciecnceIn
self.list [2] = enginerIn
self.list [3] = businessIn
}
}
var spaceElev = resProj(
mathsP: 10,
scienceP: 20,
enginerP: 30,
businessP: 5)
var x = false
while x == false{
//wait function here pls//
print("tick", terminator:"?")
let y = readLine()
if y == "y"{
spaceElev.tick()
}
else{
print("gotta put y")
}
var templist = spaceElev.projReq
var templistcount = 0
templistcount = templist.count
for loop in 0..<templistcount{
if templist[loop] == 0{
templistcount -= 1
}
}
if templistcount == 0 {
x = true
print("project completed")
}
}
}
Where it says //wait function here pls// I would like to make the program wait for 1 second.
There are a lot of way to do this but most common way is create a completion function. For example:
func doSth(_ someParameter: String, _ completion: ()->()) {
print(someParameter)
// After your code is finish call completion
completion()
}
And when you call (there is two way to call):
doSth("Done") {
print("You can be sure that this block will work after your func finish")
}
or you can simply create another func and send it as a parameter.
You can also use DispatchQueue:
DispatchQueue.main.asyncAfter(deadline: .now()+1) {
// put your func here...
}
You can simple use the UNIX-Functin func sleep(_: UInt32) -> UInt32.
In your case use sleep(1) to wait one second.
You could use Grand Central Dispatch or perform.
GCD solution:
let delayInSeconds = 1
DispatchQueue.main.asyncAfter(deadline: .now() + delayInSeconds) {
print("tick", terminator:"?")
}
If you want to learn more about Grand Central Dispatch (GCD) I suggest you read through this:
Grand Central Dispatch - Wikipedia
Grand Central Dispatch Tutorial - Ray Wenderlich
Perform solution:
Create a function like this:
#objc func delayedFunc() {
//write the code here that you want to execute with a one second delay
}
Then call this where you want the delayed function to execute:
let delayInSeconds = 1
perform(#selector(delayedFunc), with: nil, afterDelay: delayInSeconds)
You can use the RunLoop class:
func wait(for interval: TimeInterval) {
RunLoop.current.run(until: Date() + interval)
}
I have a simple piece of code that I guess I'm using local and global variables in it. But, I have a hard time understanding what's going wrong in here. I am setting "var hhhh:Int = 0" at first. Then, inside the if statement, I set "hhhh = appleCount["count"] as! Int". Since appleCount["count"] is not zero and has some value, hhhh gets its' value (I tried that uisng a print statement and hhhh is not zero inside if statement), but, later when I print hhhh with print("(hhhh)") outside if, I again get zero for its' value. Does it have something to do with local and global variables? I'm trying to communicate with Parse in the code by the way.
Thanks a lot for your kind help
import UIKit
import Parse
class NewsPageViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad(
var hhhh:Int = 0
var tttt:Int = 0
var cccc:Int = 1
if cccc == 1 {
var query = PFQuery(className: "Count")
query.getObjectInBackgroundWithId("RhC25gVjZm", block: { (object: PFObject?, error: NSError?) -> Void in
if error != nil {
print(error)
} else if let appleCount = object {
appleCount["count"] = appleCount["count"] as! Int + 1
hhhh = appleCount["count"] as! Int
appleCount.saveInBackground()
}
})
}
print(hhhh)
}
}
It does not have to do with local and global variables. It has to do with background threads. The code in brackets {} after the parameter label "block" will run in a background thread at a later time.
Your print(hhhh) is running before the block has had a chance to change hhhh. Move the print statement back inside the block so you can see the variable being set.
osteven response helped me a lot understanding the problem. Thanks a lot man. In addition to osteven's response, I just waned to add that a major part of my problem was coming because I was trying to do some mathematical operations on the objects I was trying to save in Parse. So, I also figured that I could create an array, save my objects inside that array, and then access the key and update the values. Here is a sample code of what I am using right now. It does some mathematical operation on two different objects saved in Parse and updates the label's text on screen. For accessing the two objects in Parse and updating them I'm using an array.
Hope the answers here will help someone in future as the awesome people of StackOverFlow are helping me now.
Peace!
var hhhh : [Int] = []
#IBOutlet weak var jPercent: UILabel!
#IBOutlet weak var yPercent: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
var query = PFQuery(className: "Count")
if cccc == 1 {
query.getObjectInBackgroundWithId("DcU9tdRdnl", block: { (object: PFObject?, error: NSError?) -> Void in
if error != nil {
print(error)
} else if let jCount = object {
jCount["count"] = jCount["count"] as! Int + 1
jCount.saveInBackground()
}
})
} else if cccc == 2 {
query.getObjectInBackgroundWithId("5Bq4HJbFa3", block: { (object: PFObject?, error: NSError?) -> Void in
if error != nil {
print(error)
} else if let yCount = object {
yCount["count"] = yCount["count"] as! Int + 1
yCount.saveInBackground()
}
})
}
//shouldn't use same query for findObjectsInBackgroundWithBlock and getObjectInBackgroundWithId otherwise you'll get a runtime error
var query2 = PFQuery(className: "Count")
query2.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if let users = objects {
for object in users {
if let user = object["count"] as? Int {
self.hhhh.append(user)
}
}
}
var gggg = 100*Float(self.hhhh[0])/(Float(self.hhhh[0]+self.hhhh[1]))
self.yPercent.text = String(format: "%.1f", gggg) + "%"
self.jPercent.text = String(format: "%.1f", 100 - gggg) + "%"
print(self.hhhh[0])
}
}
I've write a simple code:
extension String {
func trailingSpaces (width: Int) -> String {
var s = "\(self)"
for i in count(s)..<width {
s = s + " "
}
return s
}
func leadingSpaces (width: Int) -> String {
var s = "\(self)"
for i in count(s)..<width {
s = " " + s
}
return s
}
}
class ViewController: UIViewController {
var users = ["Marco", "Gianni", "Antonio", "Giulio", "Franco"]
var ages = [29, 45, 17, 33, 37]
override func viewDidLoad() {
super.viewDidLoad()
var merged = [String: Int] ()
var totalAge = 0.0
for var i = 0; i < ages.count; i++ {
merged[users[i]] = ages[i]
}
for user in sorted(merged.keys) {
let age = merged[user]
totalAge += Double(age!)
let paddedUser = user.trailingSpaces(10)
let paddedAge = "\(age)".leadingSpaces(3)
println("\(paddedUser) \(age!)")
}
println("\n\(merged.count) users")
println("average age: \(totalAge / Double(merged.count))")
}
}
but I can't make it work the leadingSpaces function and I can't understand the reason, it's quite identical to the other extension func that works.
It give the error
fatal error: Can't form Range with end < start
on runtime
in case you run into this kind of problem, always do a println() of the variable you are using
println("\(age)") right before let paddedAge = "\(age!)".leadingSpaces(3)
reveals the problem
age is an optional, meaning that you are trying to do the padding on a String which has this value "Optional(17)"
Thus, your count(s) is higher than 3, and you have an invalid range
Your variable age is not an Int - it's an optional - Int?. You know this already as you are unwrapping it in the lines totalAge += Double(age!) and println("\(paddedUser) \(age!)") - but you are not unwrapping it in the failing line let paddedAge = "\(age)".leadingSpaces(3). The string being passed to leadingSpaces is not "17", it's "Optional(17)", which is why your padding function is failing, as the length is greater than the requested width.
Having said that, as the commentator #milo256 points out, Swift can only iterate upwards, and so unless you put a check on width >= .count in your padding functions they will crash at some point.
class ViewController: UIViewController {
#IBOutlet weak var inputField: UITextField!
#IBOutlet weak var output: UITextView!
var guesses : UInt = 0
var number : UInt32 = 0
var gameOver = false
let MAX_GUESSES : UInt = 8
#IBAction func guess(sender: UIButton) {
var possibleGuess : Int? = inputField.text.toInt()
if let guess = possibleGuess {
// possibleGuess exists!
} else {
consoleOut("Please input a valid number!\n")
clearInput()
}
if UInt32(guess) > Int(number) {
consoleOut("\(guess): You guessed too high!\n")
++guesses
} else if UInt32(guess) < number {
consoleOut("\(guess): You guessed too low!\n")
++guesses
} else {
consoleOut("\n\(guess): You win!\n")
consoleOut("Go again? (Y)")
guesses = 0
gameOver = true
}
clearInput()
if (guesses == MAX_GUESSES) {
consoleOut("\nYou lose :(\n")
consoleOut("Go again? (Y)")
guesses = 0
gameOver = true
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
number = generateNewNumber()
consoleOut("Gondolkodom egy számot...\n")
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func consoleOut(text : String) {
output.text = output.text + text
}
func generateNewNumber () -> UInt32 {
return arc4random_uniform(100)
}
func clearInput() {
inputField.text = ""
}
}
This is the code that I use and I get the error message at if UInt32(guess) > Int(number) {. I really can't get through this.
(swift) Error: can not invoke '>' with an argument list of type '(UInt32, #lvalue UInt32)'
* This is not exactly your problem, but it may show you a way to get around it :) *
This must be a Swift bug like many others ObjectiveC had.
I'm having the same problem trying to compare an arc4random() number (which is an UInt32 type) with a UInt32() casted string, and I get the same error, which is more outrageous in my case because the two numbers ARE the same type. Which leads me to think that the casting must not be producing the desired result.
I though of creating an auxiliary UIint32 variable and assign it UInt32(theString), butSwift doesn't let you convert a String into UInt32 when defining a variable, so I had to create an auxiliary variable to be converted to Int, and then convert the Int to UInt32 to be able to compare the two numbers:
var theString = "5"
var randomNumber = arc4random() % 10
var UInt32Number = UInt32(theString)
// => ERROR: "Cannot invoke 'init' with an argument of type '#lvalue String!'
// (this is where I realized the comparison line could be suffering from the same problem)
if randomNumber == UInt32(theString) { ... }
// No error here 'cos Swift is supposed to have casted theString into a UInt32
// ...but surprisingly it prompts an ERROR saying it can't compare a UInt32 with a UInt32 (WTF!)
// And here's where I go crazy, because watch what happens in the next lines:
var intValue = theString.toInt()
var UInt32Value = UInt32(intValue!)
if randomNumber == UInt32Value { ... } // => NOW IT WORKS!!
CONCLUSION: Swift is not making the conversion type in the comparison even if it's supposed to. Sometimes it seems to f*** up. Using auxiliary variables with set types can get around the problem.