I have a long string in swift3 and want to check if it contains word1 and word2. It could also be more than 2 search words. I found out following solution:
var Text = "Hello Swift-world"
var TextArray = ["Hello", "world"]
var count = 0
for n in 0..<TextArray.count {
if (Text.contains(TextArray[n])) {
count += 1
}
}
if (count == TextArray.count) {
print ("success")
}
But this seems very complicated, is there not an easier way to solve this? (Xcode8 and swift3)
If you are looking for less code:
let text = "Hello Swift-world"
let wordList = ["Hello", "world"]
let success = !wordList.contains(where: { !text.contains($0) })
print(success)
It is also a little more efficient than your solution because
the contains method returns as soon as a "not contained" word
is found.
As of Swift 4 or later, you can use allSatisfy:
let success = wordList.allSatisfy(text.contains)
A more Swifty solution that will stop searching after it found a non-existent word:
var text = "Hello Swift-world"
var textArray = ["Hello", "world"]
let match = textArray.reduce(true) { !$0 ? false : (text.range(of: $1) != nil ) }
Another way to do it which stops after it found a non-match:
let match = textArray.first(where: { !text.contains($0) }) == nil
Another possibility is regular expressions:
// *'s are wildcards
let regexp = "(?=.*Hello*)(?=.*world*)"
if let range = Text.range(of:regexp, options: .regularExpression) {
print("this string contains Hello world")
} else {
print("this string doesn't have the words we want")
}
Related
I have a complicated AppleScript that returns a list of strings that I need to access from Swift. I've boiled it down to a simple example and I just can't figure out how to map the AppleScript strings to an array of Swift strings.
let listOfStringsScript = """
set listOfStrings to { "one", "two", "three" }
"""
if let scriptObject = NSAppleScript(source: listOfStringsScript) {
var errorDict: NSDictionary? = nil
let resultDescriptor = scriptObject.executeAndReturnError(&errorDict)
if errorDict == nil {
// TODO: convert the resultDescriptor (NSAppleEventDescriptor) into an array of strings
print(resultDescriptor)
// OUTPUT: <NSAppleEventDescriptor: [ 'utxt'("one"), 'utxt'("two"), 'utxt'("three") ]>
}
}
Answer with help from #Alexander and #MartinR:
extension NSAppleEventDescriptor {
func toStringArray() -> [String] {
guard let listDescriptor = self.coerce(toDescriptorType: typeAEList) else {
return []
}
return (0..<listDescriptor.numberOfItems)
.compactMap { listDescriptor.atIndex($0 + 1)?.stringValue }
}
}
...
let resultDescriptor = scriptObject.executeAndReturnError(&errorDict)
let subjectLines = resultDescriptor.toStringArray()
An alternative is to gather the Apple Script result as lines of text separated by line breaks and then parse the string in Swift.
So break up the Apple Script result using
set AppleScript's text item delimiters to linefeed
Then simply parse
let selectedItems = scriptExecuted.stringValue!
let selectedItemsFiltered = selectedItems.components(separatedBy: .newlines)
.components returns a string array
Say I have a String, how do I determine the number of words in it? I'm trying to create an extension like:
extension String {
var numberOfWords: Int {
// Insert string-counting code here
}
}
If you search "word count string swift" you'll find dozens of StackOverflow answers and gists that tell you to split the string using str.components(separatedBy: " ").count.
DON'T USE components(separatedBy:)!!!
Many non-European languages (particularly East Asian languages) don't use spaces to split words. This will also incorrectly count hyphenated words as separate, and lone punctuation as a word.
The most correct AND most performant way to solve this problem is to use either enumerateSubstrings(in:options:) or CFStringTokenizer.
// enumerateSubstrings
extension String {
var numberOfWords: Int {
var count = 0
let range = startIndex..<endIndex
enumerateSubstrings(in: range, options: [.byWords, .substringNotRequired, .localized], { _, _, _, _ -> () in
count += 1
})
return count
}
}
OR:
// CFStringTokenizer
extension String {
var numberOfWords: Int {
let inputRange = CFRangeMake(0, utf16.count)
let flag = UInt(kCFStringTokenizerUnitWord)
let locale = CFLocaleCopyCurrent()
let tokenizer = CFStringTokenizerCreate(kCFAllocatorDefault, self as CFString, inputRange, flag, locale)
var tokenType = CFStringTokenizerAdvanceToNextToken(tokenizer)
var count = 0
while tokenType != [] {
count += 1
tokenType = CFStringTokenizerAdvanceToNextToken(tokenizer)
}
return count
}
}
Both are very performant, but enumerateSubtrings(in:options:...) is about twice as fast.
Shocked that nobody is pointing this out elsewhere, so I hope people searching for a solution find this.
Count of words in a string
Create an extension of String
extension String{
var wordCount:Int{
let chararacter = CharacterSet.whitespacesAndNewlines.union(.punctuationCharacters)
let comps = components(separatedBy: chararacter)
let words = comps.filter { !$0.isEmpty }
return words.count
}
}
How to use
"This is a test string".wordCount // Result: 5
I write Swift application that parse log file.
log file string:
substr1 substr2 "substr 3" substr4
I need to get array: [substr1, substr2, substr 3, substr4]
But if I use something like:
print(stringLine.components(separatedBy: " "))
I got: [substr1, substr2, "substr, 3", substr4].
How to receive array: [substr1, substr2, substr 3, substr4]?
One of the possible solutions is to use map:
let testSting = "substr1 substr2 \"substr3\" substr4"
let mappedString = testString.components(separatedBy: " ").map({$0.replacingOccurrences(of: "\"", with: "")})
print(mappedString) //["substr1", "substr2", "substr3", "substr4"]
This case of the issue is required to use regular expression but this example is provided. So to solve problem in you're case it is possible to go in this way:
var testStingArray = testSting.replacingOccurrences(of: "\"", with: "").components(separatedBy: " ")
var arr = [String]()
var step = 0
while step < testStingArray.count {
var current = testStingArray[step]
var next = step + 1
if next < testStingArray.count {
if testStingArray[next].characters.count == 1 {
current += " " + testStingArray[next]
testStingArray.remove(at: next)
}
}
arr.append(current)
step += 1
}
print(arr)//["substr1", "substr2", "substr 3", "substr4"]
You'd better work with regular expression:
let pattern = "([^\\s\"]+|\"[^\"]+\")"
let regex = try! NSRegularExpression(pattern: pattern, options: [])
let line = "substr1 substr2 \"substr 3\" substr4"
let arr = regex.matches(in: line, options: [], range: NSRange(0..<line.utf16.count))
.map{(line as NSString).substring(with: $0.rangeAt(1)).trimmingCharacters(in: CharacterSet(charactersIn: "\""))}
print(arr) //->["substr1", "substr2", "substr 3", "substr4"]
Alternatively you could split the string based on a CharacterSet and then filter out the empty occurrences:
let stringLine = "substr1 substr2 \"substr3\" substr4"
let array = stringLine.components(separatedBy: CharacterSet(charactersIn: "\" ")).filter { !$0.isEmpty }
print (array)
Output: ["substr1", "substr2", "substr3", "substr4"]
But this will not work correctly if there is a " somewhere in one of the 'substrings', then that specific substring will also be split.
Or, simply iterate over the characters and maintain state about the quoted parts:
//: Playground - noun: a place where people can play
import UIKit
extension String {
func parse() -> [String] {
let delimiter = Character(" ")
let quote = Character("\"")
var tokens = [String]()
var pending = ""
var isQuoted = false
for character in self.characters {
if character == quote {
isQuoted = !isQuoted
}
else if character == delimiter && !isQuoted {
tokens.append(pending)
pending = ""
}
else {
pending.append(character)
}
}
// Add final token
if !pending.isEmpty {
tokens.append(pending)
}
return tokens
}
}
print ("substr1 substr2 \"substr 3\" substr4".parse()) // ["substr1", "substr2", "substr 3", "substr4"]
print ("\"substr 1\" substr2 \"substr 3\" substr4".parse()) // ["substr 1", "substr2", "substr 3", "substr4"]
print ("a b c d".parse()) // ["a", "b", "c", "d"]
Note: this code doesn't take into account that double quotes "" might be used to escape a single quote. But I don't know if that's a possibility in your case.
https://tburette.github.io/blog/2014/05/25/so-you-want-to-write-your-own-CSV-code/
a string such as ! !! yuahl! ! , I want delete ! and , when I code like this
for index in InputName.characters.indices {
if String(InputName[index]) == "" || InputName.substringToIndex(index) == "!" {
InputName.removeAtIndex(index)
}
}
have this error " fatal error: subscript: subRange extends past String end ", how should I do? THX :D
Swift 5+
let myString = "aaaaaaaabbbb"
let replaced = myString.replacingOccurrences(of: "bbbb", with: "") // "aaaaaaaa"
If you need to remove characters only on both ends, you can use stringByTrimmingCharactersInSet(_:)
let delCharSet = NSCharacterSet(charactersInString: "! ")
let s1 = "! aString! !"
let s1Del = s1.stringByTrimmingCharactersInSet(delCharSet)
print(s1Del) //->aString
let s2 = "! anotherString !! aString! !"
let s2Del = s2.stringByTrimmingCharactersInSet(delCharSet)
print(s2Del) //->anotherString !! aString
If you need to remove characters also in the middle, "reconstruct from the filtered output" would be a little bit more efficient than repeating single character removal.
var tempUSView = String.UnicodeScalarView()
tempUSView.appendContentsOf(s2.unicodeScalars.lazy.filter{!delCharSet.longCharacterIsMember($0.value)})
let s2DelAll = String(tempUSView)
print(s2DelAll) //->anotherStringaString
If you don't mind generating many intermediate Strings and Arrays, this single liner can generate the expected output:
let s2DelAll2 = s2.componentsSeparatedByCharactersInSet(delCharSet).joinWithSeparator("")
print(s2DelAll2) //->anotherStringaString
I find that the filter method is a good way to go for this sort of thing:
let unfiltered = "! !! yuahl! !"
// Array of Characters to remove
let removal: [Character] = ["!"," "]
// turn the string into an Array
let unfilteredCharacters = unfiltered.characters
// return an Array without the removal Characters
let filteredCharacters = unfilteredCharacters.filter { !removal.contains($0) }
// build a String with the filtered Array
let filtered = String(filteredCharacters)
print(filtered) // => "yeah"
// combined to a single line
print(String(unfiltered.characters.filter { !removal.contains($0) })) // => "yuahl"
Swift 3
In Swift 3, the syntax is a bit nicer. As a result of the Great Swiftification of the old APIs, the factory method is now called trimmingCharacters(in:). Also, you can construct the CharacterSet as a Set of single-character Strings:
let string = "! !! yuahl! !"
string.trimmingCharacters(in: [" ", "!"]) // "yuahl"
If you have characters in the middle of the string you would like to remove as well, you can use components(separatedBy:).joined():
let string = "! !! yu !ahl! !"
string.components(separatedBy: ["!", " "]).joined() // "yuahl"
H/T #OOPer for the Swift 2 version
func trimLast(character chars: Set<Character>) -> String {
let str: String = String(self.reversed())
guard let index = str.index(where: {!chars.contains($0)}) else {
return self
}
return String((str[index..<str.endIndex]).reversed())
}
Note:
By adding this function in String extension, you can delete the specific character of string at last.
for index in InputName.characters.indices.reversed() {
if String(InputName[index]) == "" || InputName.substringToIndex(index) == "!" {
InputName.removeAtIndex(index)
}
}
Also you can add such very helpful extension :
import Foundation
extension String{
func exclude(find:String) -> String {
return stringByReplacingOccurrencesOfString(find, withString: "", options: .CaseInsensitiveSearch, range: nil)
}
func replaceAll(find:String, with:String) -> String {
return stringByReplacingOccurrencesOfString(find, withString: with, options: .CaseInsensitiveSearch, range: nil)
}
}
you can use this:
for example if you want to remove "%" the percent from 10%
if let i = text.firstIndex(of: "%") {
text.remove(at: i) //10
}
class book{
var nameOfBook: String!
}
var englishBooks=[book(),book(),book()]
var arr = englishBooks.filter {
contains($0.nameOfBook, "rt")
}
I'm using this filter but with error cannot invoke filter with an argument
contains() checks if a sequence contains a given element, e.g.
if a String contains a given Character.
If your intention is to find all books where the name contains the substring "rt", then you can use rangeOfString():
var arr = englishBooks.filter {
$0.nameOfBook.rangeOfString("rt") != nil
}
or for case-insensitive comparison:
var arr = englishBooks.filter {
$0.nameOfBook.rangeOfString("rt", options: .CaseInsensitiveSearch) != nil
}
As of Swift 2, you can use
nameOfBook.containsString("rt") // or
nameOfBook.localizedCaseInsensitiveContainsString("rt")
and in Swift 3 this is
nameOfBook.contains("rt") // or
nameOfBook.localizedStandardContains("rt") // or
nameOfBook.range(of: "rt", options: .caseInsensitive) != nil
Sorry this is an old thread. Change you code slightly to properly init your variable 'nameOfBook'.
class book{
var nameOfBook: String!
init(name: String) {
nameOfBook = name
}
}
Then we can create an array of books.
var englishBooks = [book(name: "Big Nose"), book(name: "English Future
Prime Minister"), book(name: "Phenomenon")]
The array's 'filter' function takes one argument and some logics, 'contains' function can take a simplest form of a string you are searching for.
let list1 = englishBooks.filter { (name) -> Bool in
name.contains("English")
}
You can then print out list1 like so:
let list2 = arr1.map({ (book) -> String in
return book.nameOfBook
})
print(list2)
// print ["English Future Prime Minister"]
Above two snippets can be written short hand like so:
let list3 = englishBooks.filter{ ($0.nameOfBook.contains("English")) }
print(list3.map({"\($0.nameOfBook!)"}))
SWIFT 4.0
In order to filter objects and get resultant array you can use this
self.resultArray = self.upcomingAuctions.filter {
$0.auctionStatus == "waiting"
}
in case you want to delete an interval of object which has specific IDs (matchIDsToDelete) from an array of object (matches)
var matches = [Match]
var matchIDsToDelete = [String]
matches = matches.filter { !matchIDsToDelete.contains($0.matchID) }
2020 | SWIFT 5.1:
short answer:
books.filter { $0.alias.range(of: filterStr, options: .caseInsensitive) != nil }
long sample:
public filterStr = ""
public var books: [Book] = []
public var booksFiltered: [Book] {
get {
(filterStr.isEmpty )
? books
: books.filter { $0.alias.range(of: filterStr, options: .caseInsensitive) != nil }
}
}
I think this is more useful for lack of wrong typing situation.
englishBooks.filter( { $0.nameOfBook.range(of: searchText, options: .caseInsensitive) != nil}
In Swift 4.2 use the remove(where:) functionality. filter isn't doing well with memory, remove(where:) does the job better.
To do what you want:
englishBooks.removeAll { !$0.nameOfBook.contains("English") }