Find match in array for given string? - ios

Question

Ok so lets say I have an custom object for vocabulary words, alternate way of being written, and their meaning.
class VocabEntry {
var kanji:String?
var kana:String?
var meaning:String?
}
Then I have an array comprised of these objects. Here's one for example.
let newVocabWord = VocabEntry()
newVocabWord.kanji = "下さい”
newVocabWord.kana = "ください”
newVocabWord.meaning = "please"
Now I have a string of text:
let testString = "すみません、十階のボタンを押して下さい"
How can I compare that string to my array of custom objects (that contain strings) and reference the matches?
I tried.
if vocabArray.contains( { $0.kanji == testString }) {
print("yes")
}
But that trying to match the entire string. If I change testString to "下さい" it works, but that's not what I'm looking for. What I want is for it to say "Here I found 下さい in xx object. Here's the index number."

Answer 1

You can use indexOf() with a predicate to find the index of a
matching entry, and containsString() to search for substrings.
Since the kanji property is optional, you have to check that via
optional binding:
if let index = vocabArray.indexOf({ entry in
if let kanji = entry.kanji {
// check if `testString` contains `kanji`:
return testString.containsString(kanji)
} else {
// `entry.kanji` is `nil`: no match
return false
}
}) {
print("Found at index:", index)
} else {
print("Not found")
}
This can be written more concise as
if let index = vocabArray.indexOf({
$0.kanji.flatMap { testString.containsString($0) } ?? false
}) {
print("Found at index:", index)
} else {
print("Not found")
}
To get the indices of all matching entries, the following would work:
let matchingIndices = vocabArray.enumerate().filter { (idx, entry) in
// filter matching entries
entry.kanji.flatMap { testString.containsString($0) } ?? false
}.map {
// reduce to index
(idx, entry) in idx
}
print("Found at indices:", matchingIndices)