How to convert String to Character Array? [duplicate]

Question

So, I am stuck on this since most of the internal Swift programs don't work anymore and am still learning. I have tried a lot of things but it still doesn't work.

I have tried internal functions. I have tried custom methods. I have tried putting them in extensions (It is the same as custom methods but I wanted to practice extensions.)


extension Character {
    var isVowel: Bool {
        let vowels: [Character] = ["a", "e", "i", "o", "u"]
        return vowels.contains(self)
    }
}

extension String{
    
    func transform (_ function: (String) -> String) -> String{
        return function(self)
    }
    
    func toCharacter() -> [Character]{
        var working = self.components(separatedBy: "")
        var output: [Character] = []
        
        for i in 0...working.count{
            output.append(Character(working[i]))
        }
        
        return output
    }
}

func toString(from input: [Character]) -> String{
    var output = ""
    for i in input{
        output += String(i)
    }
    
    return output
}


func removeVowels(from given: String) -> String{

    var working = given.toCharacter()
    
    for i in 0...working.count{
        if working[i].isVowel{
            working.remove(at: i)
        }
    }
    
    return toString(from: working)
  
}

In an extension to the String type, declare a function named transform. The function should accept as an argument another function of type (String) -> String. For this argument, let's omit the external label. The transform function should also return a String.

Create a function named removeVowels that takes a string and returns a string. Name the external argument label for the parameter from. In the body of the method, return a new String literal with the vowels (in the English language) removed from the value passed in as an argument.

Nope. I tried that aswell. String Type in swift no longer conforms to Sequence protocol and hence can't be converted to Array Type explicitly using Array(String) — Mahi
– Mahi, Commented Aug 13, 2019 at 9:29
That is not correct (unless you are using Swift 3 or earlier). let s = "abc" ; let chars = Array(s) works perfectly in Swift 4 and 5. — Martin R
– Martin R, Commented Aug 13, 2019 at 9:30
Turns out, that works in Xcode but doesn't work with TreeHouse editor (that's where I am learning) Maybe they're using an older swift version. — Mahi
– Mahi, Commented Aug 13, 2019 at 9:57
For Swift 3 it would be Array(s.characters) – also covered in the above-mentioned Q&A. — Martin R
– Martin R, Commented Aug 13, 2019 at 9:59

Eternal Black · Accepted Answer · 2019-08-13 10:00:57Z

3

Beside recommending SwifterSwift as they already have that extension implemented as well as many other useful extensions, this is their implementation.

public extension String {
    /// SwifterSwift: Array of characters of a string.
    var charactersArray: [Character] {
        return Array(self)
    }
}

To be used like this:

let myString:String = "myString"
let chars:[Character] = myString.charactersArray

edited Aug 13, 2019 at 10:00

answered Aug 13, 2019 at 9:39

Eternal Black

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