simple Swift function with Xcode - swift

Question

I am trying to program a simple function and am having some trouble. The purpose of the function is to take a String and if the String does not start with a consonant, remove each vowel until you reach the first consonant. For example if the given String was "eat" the function would return "t". If the given String was "awesome" it would return "wesome"
Below is my code, it compiles without error but I cannot get the desired output. Right now it just outputs an empty string. id appreciate any advice, Thanks

Answer 1

This would be the correct and efficient solution:
func removeFirstLetter(word: String) -> String {
var lyricalWord = word
let vowelArray = ["a", "e", "i", "o", "u", "y"]
for _ in lyricalWord {
// We are moving these to the loop so every time we get updated first character
var firstCharacter = lyricalWord[lyricalWord.startIndex]
var str = String(firstCharacter)
if vowelArray.contains(str) {
lyricalWord.remove(at: lyricalWord.startIndex)
} else {
// If this time the first character is consonant that means our string is ready and we can return it and finish the loop
return lyricalWord
}
}
return lyricalWord
}
print(removeFirstLetter(word: "aeiouty"))
But it can even be improved!
In your loop you iterate every time through the whole array of vowel. However, you have a nice structure called Set which works like hash table.
In simple words, while the function "contains():" calls your array 6 times to compare the letter with every vowel, the same implementation with Set makes only 1 call(not always, but most of the time)! And it's especially profitable when you gonna have bigger collections of data to compare with.
So, here goes the implementation with Set:
func removeFirstLetter(word: String) -> String {
var lyricalWord = word
let vowelArray: Set<String> = ["a", "e", "i", "o", "u", "y"] // The only change is here!
for _ in lyricalWord {
var firstCharacter = lyricalWord[lyricalWord.startIndex]
var str = String(firstCharacter)
if vowelArray.contains(str) {
lyricalWord.remove(at: lyricalWord.startIndex)
} else {
return lyricalWord
}
}
return lyricalWord
}
print(removeFirstLetter(word: "aeiouty"))

Answer 2

Two lines below the position are invalid.
let firstCharacter = lyricalworld[lyricalworld.startIndex]
let str = String(firstCharacter)
Please put it inside the for door.
for _ in lyricalworld {
let firstCharacter = lyricalworld[lyricalworld.startIndex]
let str = String(firstCharacter)
if vowelArray.contains(str){
lyricalworld.remove(at: lyricalworld.startIndex)
}
}
Full Source
func removeFirstLetter(word: String) -> String{
var lyricalworld = word
let vowelArray = ["a", "e", "i", "o", "u", "y"]
for _ in lyricalworld {
let firstCharacter = lyricalworld[lyricalworld.startIndex]
let str = String(firstCharacter)
if vowelArray.contains(str){
lyricalworld.remove(at: lyricalworld.startIndex)
}
}
return lyricalworld
}