Check if a string exists in an array case insensit

问题:

Declaration:

let listArray = ["kashif"]
let word = "kashif"

then this

contains(listArray, word) 

Returns true but if declaration is:

let word = "Kashif"

then it returns false because comparison is case sensitive.

How to make this comparison case insensitive?

回答1:

you can use

word.lowercaseString 

to convert the string to all lowercase characters

回答2:

let list = ["kashif"]
let word = "Kashif"

if contains(list, {$0.caseInsensitiveCompare(word) == NSComparisonResult.OrderedSame}) {
    println(true)  // true
}

Xcode 7.3.1 • Swift 2.2.1

if list.contains({$0.caseInsensitiveCompare(word) == .OrderedSame}) {
    print(true)  // true
}

Xcode 8 • Swift 3 or later

if list.contains(where: {$0.caseInsensitiveCompare(word) == .orderedSame}) {
    print(true)  // true
}

alternatively:

if list.contains(where: {$0.compare(word, options: .caseInsensitive) == .orderedSame}) {
    print(true)  // true
}

回答3:

Try this:

let loword = word.lowercaseString
let found = contains(listArray) { $0.lowercaseString == loword }

回答4:

For checking if a string exists in a array (case insensitively), please use

listArray.localizedCaseInsensitiveContainsString(word) 

where listArray is the name of array and word is your searched text

This code works in Swift 2.2

回答5:

SWIFT 3.0:

Finding a case insensitive string in a string array is cool and all, but if you don't have an index it can not be cool for certain situations.

Here is my solution:

let stringArray = ["FOO", "bar"]()
if let index = stringArray.index(where: {$0.caseInsensitiveCompare("foo") == .orderedSame}) {
   print("STRING \(stringArray[index]) FOUND AT INDEX \(index)")
   //prints "STRING FOO FOUND AT INDEX 0"                                             
}

This is better than the other answers b/c you have index of the object in the array, so you can grab the object and do whatever you please :)

回答6:

Swift 4

Just make everything (queries and results) case insensitive.

for item in listArray {
    if item.lowercased().contains(word.lowercased()) {
        searchResults.append(item)
    }
}

回答7:

For checking if a string exists in a array with more Options(caseInsensitive, anchored/search is limited to start)

using Foundation range(of:options:)

let list = ["kashif"]
let word = "Kashif"


if list.contains(where: {$0.range(of: word, options: [.caseInsensitive, .anchored]) != nil}) {
    print(true)  // true
}

if let index = list.index(where: {$0.range(of: word, options: [.caseInsensitive, .anchored]) != nil}) {
    print("Found at index \(index)")  // true
}

回答8:

My example

func updateSearchResultsForSearchController(searchController: UISearchController) {
    guard let searchText = searchController.searchBar.text else { return }
    let countries = Countries.getAllCountries()
    filteredCountries = countries.filter() {
        return $0.name.containsString(searchText) || $0.name.lowercaseString.containsString(searchText)
    }
    self.tableView.reloadData()
}