i have 3 Doubles, their values are random, and i am trying to achieve a comparison between them
so my code is
let double1 = 10.00 // notes: they're all random between 1-100 so i don't know what this will be
let double2 = 7.66
let double3 = 6.43
but, i tried
if (double1?.isLess(than: 50.0))! {
print("Low")
} else {
print("High")
}
but as i mentioned, this can't be done due to the random values, i need to compare two of them to each other, to make sure that one of them will be higher
Its actually rather very simple:
let maxDouble = max(max(double1, double2), double3) // prints 10
Related
I am building an app that the user selects a multiplication table. Then it gives random numbers to multiplicate with the number they select. for example, if the user selects "1". the questions shown would be "1 x 1", or "1 x 8".
The problem is that I need to assign the same random number to 2 variables. The one that will be shown on the question and the one used to calculate the result.
I thought of something like this, but the random number is different on each variable. What can I do to use the same random number generated on 2 variables?
func game() -> (String, Int) {
let randomNumber = multiplicate.randomElement()
switch selectedQuestion {
case 0:
return ("1 × \(randomNumber!)", 1 * randomNumber!)
default:
return ("", 0)
}
}
Not exactly sure what you're asking but you could do something like this:
let number = Int.random(in: 0..<10)
let number2 = number
but I don't think there is a need to create a new variable for this. The whole idea of variables is that you can save some value and then use it later so there isn't really a need to create number2 here.
I am trying to store all numbers that the random number generator generate. After that the number generator needs to check if the number already was generated and if so it will keep generate a new number until all number for example 1 to 30 are generated. I have so far only the random number generator:
if let Aantalvragen = snapshot?.data()!["Aantal vragen"] as? String {
self.AantalVragenDef = Aantalvragen
}
let RandomVraag = Int(arc4random_uniform(UInt32(self.AantalVragenDef)!) + 1)
AantalVragenDef is an number that indicates how many questions there are. So the generator knows how far it can generate. Please help.
The easiest is probably to create an array or list and fill it with the numbers 1 to n that you want, shuffle it and then use the numbers in the order they appear. That way you are guaranteed that each number show up exactly once.
See how to shuffle an array in Swift
I believe what you are trying to get is a random generator that generates numbers from 1 to the number of questions, but if the number already exists, you don't want to keep it. I suggest using if-else statements and arrays.
The code might look something like this:
if let Aantalvragen = snapshot?.data()!["Aantal vragen"] as? String {
self.AantalVragenDef = Aantalvragen
}
var array = [Int]()
while array.count != self.AantalVragenDef {
let RandomVraag = Int(arc4random_uniform(UInt32(self.AantalVragenDef)!) + 1)
if array.contains(RandomVraag) == false {
array.append(RandomVraag)
}
}
This loop will continue until there are (number of questions) integers in the array. Let me know if this is what you are looking for.
Good Luck, Arnav
What I want to do is populate an Array (sequence) by appending in the elements of another Array (availableExercises), one by one. I want to do it one by one because the sequence has to hold a given number of items. The available exercises list is in nature finite, and I want to use its elements as many times as I want, as opposed to a multiple number of the available list total.
The current code included does exactly that and works. It is possible to just paste that in a Playground to see it at work.
My question is: Is there a better Swift3 way to achieve the same result? Although the code works, I'd like to not need the variable i. Swift3 allows for structured code like closures and I'm failing to see how I could use them better. It seems to me there would be a better structure for this which is just out of reach at the moment.
Here's the code:
import UIKit
let repTime = 20 //seconds
let restTime = 10 //seconds
let woDuration = 3 //minutes
let totalWOTime = woDuration * 60
let sessionTime = repTime + restTime
let totalSessions = totalWOTime / sessionTime
let availableExercises = ["push up","deep squat","burpee","HHSA plank"]
var sequence = [String]()
var i = 0
while sequence.count < totalSessions {
if i < availableExercises.count {
sequence.append(availableExercises[i])
i += 1
}
else { i = 0 }
}
sequence
You can overcome from i using modulo of sequence.count % availableExercises.count like this way.
var sequence = [String]()
while(sequence.count < totalSessions) {
let currentIndex = sequence.count % availableExercises.count
sequence.append(availableExercises[currentIndex])
}
print(sequence)
//["push up", "deep squat", "burpee", "HHSA plank", "push up", "deep squat"]
You can condense your logic by using map(_:) and the remainder operator %:
let sequence = (0..<totalSessions).map {
availableExercises[$0 % availableExercises.count]
}
map(_:) will iterate from 0 up to (but not including) totalSessions, and for each index, the corresponding element in availableExercises will be used in the result, with the remainder operator allowing you to 'wrap around' once you reach the end of availableExercises.
This also has the advantage of preallocating the resultant array (which map(_:) will do for you), preventing it from being needlessly re-allocated upon appending.
Personally, Nirav's solution is probably the best, but I can't help offering this solution, particularly because it demonstrates (pseudo-)infinite lazy sequences in Swift:
Array(
repeatElement(availableExercises, count: .max)
.joined()
.prefix(totalSessions))
If you just want to iterate over this, you of course don't need the Array(), you can leave the whole thing lazy. Wrapping it up in Array() just forces it to evaluate immediately ("strictly") and avoids the crazy BidirectionalSlice<FlattenBidirectionalCollection<Repeated<Array<String>>>> type.
I am new in Swift.
I am trying to make a budget application. This app have a Calculator like keyboard. My idea is when users enter the money app will automatically add a decimal place for users.
For example, if you type 1230 it will give you 12.30 and type 123 it will display 1.23
I wrote a couple lines of code down below. The problem is it only can add decimal point after first digit it won't go backwards when you give more digits. It only can display as X.XXXXX
I tried solve this problem with String.index(maybe increase index?) and NSNumber/NSString format. But I don't know this is the right direction or not.
let number = sender.currentTitle!
let i: String = displayPayment.text!
if (displayPayment.text?.contains("."))!{
displayPayment.text = i == "0" ? number : displayPayment.text! + number
}
else {
displayPayment.text = i == "0" ? number : displayPayment.text! + "." + number
}
Indexing Strings in Swift is not as "straightforward" as many would like, simply due to how Strings are represented internally. If you just want to add a . at before the second to last position of the user input you could do it like this:
let amount = "1230"
var result = amount
if amount.characters.count >= 2 {
let index = amount.index(amount.endIndex, offsetBy: -2)
result = amount[amount.startIndex..<index] + "." + amount[index..<amount.endIndex]
} else {
result = "0.0\(amount)"
}
So for the input of 1230 result will be 12.30. Now You might want to adjust this depending on your specific needs. For example, if the user inputs 30 this code would result in .30 (this might or might not be what you want).
I have two variables, string0 and string1. I want to randomly set a label to one of those strings. I tried generating the variable name using a random number like this:
let string0a = "\(Name!) sees something that offends \(Gender!)."
let string1a = "\(Name!) saw Star Wars earlier."
let number = arc4random_uniform(1)
text1.text = string\(number!)a
What is the best way to randomly set the label text to one of the two strings?
You can't generate variable names at runtime in Swift because they are used at compile time. This is what arrays were invented for:
let strings = [string0a, string1a]
let number = Int(arc4random_uniform(2))
text1.text = strings[number]
or more concisely:
text1.text = [string0a, string1a][Int(arc4random_uniform(2))]