iOS repl.it - Optionals Challenge Solution

optionals.swift

//Don't change this
var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {
  
  //Write your code here.
  let a = studentsAndScores["Amy"]!
  let b = studentsAndScores["James"]!
  let c = studentsAndScores["Helen"]!
  
  var temp = 0
  //If a is greater than b
  if a > temp {
    //And a is also greater than c
    temp = a
  }
    
  if b > temp {
    temp = b
  }
  
  if c > temp {
    temp = c
  }
  
  print(temp)
  
  
}

//Don't change this
highestScore(scores: studentsAndScores)

I totally misunderstood this challenge

I did't knew why there was the readLine() function in this challenge. By checking the documentation it is used when user enters a value from the standard input (is this the keyboard?).

So, I solved this challenge by declaring the studentAndscores var as follows:
var studentAndscores : [String : Int]
And so, inside the highestScore func i used the scores object like this:
let amyScore = scores["Amy"]!
let jamesScore = scores["James"]!
let helenScore = scores["Helen"]!
This way it works perfectly!

I did not understand this at all. Anyone I can ask a question to understand it better?

//Don't change this
var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

print(studentsAndScores.values.max()!)

}

highestScore(scores: studentsAndScores)

I did't knew why there was the readLine() function in this challenge. By checking the documentation it is used when user enters a value from the standard input (is this the keyboard?).

So, I solved this challenge by declaring the studentAndscores var as follows:
var studentAndscores : [String : Int]
And so, inside the highestScore func i used the scores object like this:
let amyScore = scores["Amy"]!
let jamesScore = scores["James"]!
let helenScore = scores["Helen"]!
This way it works perfectly!

That readline() is used get the input from the person and in this case the values are not given.
after your function you can try to use highestScore(scores: studentsAndScores) to get the input. once your function run compiler will ask u for the input.

I'm stumped. I applied the solution at the top, but have not had any luck with printing the sample values. I know the solution works but when I try to apply the following 'var studentsAndScores = ["Amy": 88, "James": 55, "Helen": 99]' I just get a bunch of

frame #8: 0x000000018b9c2740 GraphicsServices`GSEventRunModal + 160
frame #9: 0x00000001843ccbf0 UIKitCore`-[UIApplication _run] + 964
frame #10: 0x00000001843d19d0 UIKitCore`UIApplicationMain + 112
frame #11: 0x0000000100696f7c MyPlayground`main + 216
frame #12: 0x0000000180223cbc libdyld.dylib`start + 4

I wrote the below code, it works completely fine on playground when you call the function, but on Udemy it dosent seem to accept it.

var studentsAndScores = ["Amy": 10, "James": 20, "Helen": 99]

func highestScore(scores: [String: Int]) {

//Write your code here.
var highScore: Int? = 0

for i in studentsAndScores {
if i.value > highScore! {
highScore = i.value
}

}
print(highScore!)

}
highestScore(scores: studentsAndScores)

I keep encountering an error with the Int(readLine()!)! and have been deleting that first line in the recent few Exercises. Can someone help to explain why?

Wrote the following which seems to work, but is not an accepted answer.

var studentsAndScores = ["Amy": 88, "James": 33, "Helen": 9]

func highestScore() {
    let scores = Array(studentsAndScores.values)
    print(scores.max()!)
}
highestScore()

Ah, I totally misunderstood the challenge then. I looked it up on Google/Stack Overflow and came up with:
print(scores.values.max()!)...

Came to similar conclusion.

The solution is simple and elegant, I went with the Google, StackOverflow and a more advanced option though (hehe):

func highestScore(scores: [String: Int]) {

//Write your code here.
guard let amyScore: Int = scores["Amy"], let jamesScore: Int = scores["James"], let helenScore: Int = scores["Helen"] else {
print("Some value is nil")
return
}

if amyScore > jamesScore && amyScore > helenScore {
print(amyScore)
} else if jamesScore > amyScore && jamesScore > helenScore {
print(jamesScore)
} else {
print(helenScore)
}

}

I am not sure am i technically right, this is my solution:

//Don't change this
var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {
  
  var maxScore =  0
  
  for (_, score) in studentsAndScores {
    if (maxScore < score) {
      maxScore = score
    }
  }
  print(maxScore)
}

//Don't change this
highestScore(scores: studentsAndScores)

I have been trying to run the tasks on playground for a while but i keep getting this error. Can anyone explain what optional value is talking about and how to fix this please.

This is my solution in Angela challenge test... Worked..

//Don't change this
var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

//Write your code here.
var tertinggi: Int = studentsAndScores["Amy"]!
if studentsAndScores["James"]! > tertinggi {
tertinggi = studentsAndScores["James"]!

}else if studentsAndScores["Helen"]! > tertinggi {
    tertinggi = studentsAndScores["Helen"]!
}else {
    tertinggi = studentsAndScores["Amy"]!
}
print(tertinggi)

//Write your code here.

}

What does the var temp stand for? what do you mean by temp.

This was my solution:

    let amysScore = scores["Amy"]!
    let jamesScore = scores["James"]!
    let helenScore = scores["Helen"]!
 
    if helenScore > jamesScore && helenScore > amysScore {
        print(helenScore)
    } else if amysScore > jamesScore && amysScore > helenScore {
        print(amysScore)
    } else {
        print(jamesScore)
    }

hi guys this what i did it looks pretty much the same like other

let a = studentsAndScores["Amy"]!
let b = studentsAndScores["James"]!
let c = studentsAndScores["Helen"]!
if a > b && a > c{
print(a)
}else if b > a && b > c{
print(b)
}else if c > a && c > {
print(c)
}else{
print("Error")
}

My Solution (Similar to others, took a while until I understood the task)

`//Don't change this
var studentsAndScores = ["Amy": 25, "James": 27, "Helen": 30]

func highestScore(scores: [String: Int]) {

//Write your code here.
let amy = studentsAndScores["Amy"]!
let james = studentsAndScores["James"]!
let helen = studentsAndScores["Helen"]!

if amy > james && amy > helen {
print(amy)
}
else if james > amy && james > helen {
print(james)
}
else if helen > amy && helen > james {
print(helen)
}
else {
print("Error: Value not found.")
}

}

highestScore(scores: studentsAndScores)`

//Don't change this
// var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {
print(scores.values.max()!)

}

//Try some different scores.
//Dont add the lines below to udemy!

highestScore(
scores: [
"Amy": 78,
"James": 65,
"Helen": 99
]
)

This worked perfectly for me, I don't understand, if you guys can explain, why I have to create a variable if I already can store the same inside of the function and get the result more clean and in a short way??

Well this is my solution, it passed successfully in Udemy when I checked solution. But in Replit I couldn't check because it is not printing the values. I hope that this is also correct, I understand the task, bud can someone confirm if it is correct way as well?

//Don't change this
var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

//Write your code here.
let Amy = studentsAndScores["Amy"]!
let James = studentsAndScores["James"]!
let Helen = studentsAndScores["Helen"]!

if Amy > James && Amy > Helen {
print(Amy)
} else if James > Amy && James > Helen {
print(James)
} else if Helen > James && Helen > Amy {
print(Helen)
}

}

I can't see a point of watching tutorials like this to find the solution by yourself on the Internet. I hoped that the challenges I encounter in this tutorial were going to match what has been presented before. This time I'm actually disappointed. I don't even understand the code starting with the var temp = 0. I think it would be quicker to find the solution as other people did on stack overflow.

I have managed to write the following code.

Shall also try using switch case.

var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {
  

  if 
  
  scores["Amy"]! > scores["James"]! && scores["Amy"]! > scores["Helen"]! {
    print(scores["Amy"]!)
  } 

    else if
      
    scores["James"]! > scores["Helen"]! && scores["James"]! > scores["Amy"]! {
       print(scores["James"]!)
      
    }

    else {
      
       print(scores["Helen"]!)
    }

  }

highestScore(scores: studentsAndScores)

(Ignore indentation)

I run this code on Replit and it works fine. But when I run the same code on playgrounds, the program crashes with the error.

**Fatal error: Unexpectedly found nil while unwrapping an Optional value
Playground execution failed:

error: Execution was interrupted, reason: EXC_BREAKPOINT (code=1, subcode=0x18f6dd21c).
The process has been left at the point where it was interrupted, use "thread return -x" to return to the state before expression evaluation.**

Why I don't get this error on Replit but only on the playground? I am not sure what do I write in the if statement to prevent force unwrap the optional string. Can anyone help pleaae?

Tried this and it works -

var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

//Write your code here.

let maxScore = (scores.values.max())!
if maxScore > 0 {
print(maxScore)
}

}

Like the solution but tried avoiding forced unwrapping and it worked:

var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

//Write your code here.

let a = studentsAndScores["Amy"]
let b = studentsAndScores["James"]
let c = studentsAndScores["Helen"]

var temp = 0

if let a = a {
if a > temp { temp = a }
}
if let b = b {
if b > temp { temp = b }
}
if let c = c {
if c > temp { temp = c }
}
print(temp)
}

highestScore(scores: studentsAndScores)

//Don't change this
var studentsAndScores = ["Amy": 78, "James": 55, "Helen": 86]

func highestScore(scores: [String: Int]) {

//Write your code here.

let amyScore = scores ["Amy"]!
let jamesScore = scores ["James"]!
let helenScore = scores ["Helen"]!

var Ttemp = 0

if amyScore > Ttemp {
    Ttemp = amyScore
}  
if jamesScore > Ttemp{
    Ttemp = jamesScore
} 
if helenScore > Ttemp{
    Ttemp = helenScore
}
print (Ttemp)

}

//the result is 86 not 99, the hellen score must be changed to 86, in order to solve the challenge

it didn't pass but my answer is the simplest?

var studentsAndScores = ["Amy": 88, "James": 55, "Helen": 99]

func highestScore() {

print("\(studentsAndScores.values.max()!)")
}
highestScore()

There is no need to create a variable called temp

var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

// Store the scores and force unwrap it

 let a = studentsAndScores["Amy"]!
 let b = studentsAndScores["James"]!
 let c = studentsAndScores["Helen"]!
    
// Create a nested if statement

    if a > b{
         if a > c{
             print(a)
         }
     }
     if b > c{
         if b > a{
             print(b)
         }
     }
     if c > a{
         if c > b{
             print(c)
         }
     }
}

Here's how I solved this exercise:

//Don't change this
var studentsAndScores = ["Amy": Int(readLine()!)!, "James": Int(readLine()!)!, "Helen": Int(readLine()!)!]

func highestScore(scores: [String: Int]) {

//Write your code here.
let a = studentsAndScores["Amy"]!
let b = studentsAndScores["James"]!
let c = studentsAndScores["Helen"]!

if a > b && a > c {
print(a)
} else if b > a && b > c {
print(b)
} else {
print(c)
}

}

// List of students with their scores
var studentsAndScores = ["Amy": 10, "James": 5, "Helen": 7]

// Function that takes a dictionary as a parameter to find and print the highest score among students
func highestScore(scores: [String: Int]) {
    print(studentsAndScores.values.max()!)
}

// We call the function and pass studentsAndScores dictionary as an argument
highestScore(scores: studentsAndScores) // Output: 10