Say, I have the following fullnames:
1) Whitney Rajakanya SiriVana Giovendi
2) Cheryl Thompson Winston
How to retrieve the middlename from the above respective fullname?
Example:
There are 2 middle names in name (1), and there is one middle name in name(2)
I used this code but it didn't get the middle name.
var components = fullName.components(separatedBy: " ")
if(components.count > 0)
{
let firstName = components.removeFirst()
}
Problem:
1) How get all the middle names in a name? Some names have 1 or more (like shown above).
Thanks
If you define "middle name" as everything except the first and last word in a name, then you can split the string by spaces, dropFirst and dropLast, then join the result.
var components = fullName.components(separatedBy: " ")
if (components.count <= 2) {
// no middle name
} else {
let middleName = components.dropFirst().dropLast().joined(separator: " ")
}
You can also make use of PersonNameComponentsFormatter if the names are from various locales and you need different ways of handling each of them.
you can define a greedy reg-exp and get the middle names easily, like:
let namesArray = ["Whitney Rajakanya SiriVana Giovendi", "Cheryl Thompson Winston", "James T. Kirk", "Jean-Luc Picard", "J. Archer"]
if let regExp = try? NSRegularExpression(pattern: " (.*) ", options: .caseInsensitive) {
namesArray.forEach { (name) in
regExp.matches(in: name, options: .reportProgress, range: NSRange(location: 0, length: name.count)).forEach({ (textCheckingResult) in
guard textCheckingResult.numberOfRanges > 1 else { return }
let middleNames = (name as NSString).substring(with: textCheckingResult.range(at: 1))
debugPrint("\(middleNames)")
})
}
}
then you can see the middle names printed out, like:
Rajakanya SiriVana
Thompson
T.
that could be a clean and sleek solution.
NOTE: logically it is not clear whether the shortened middle names should be filtered out or not, but you can get the gist and will be able to extend this concept at your convenince.
Related
I am trying to identify keys word in user entry to search for, so I thought of filtering out some parts of speech in order to extract key words to query in my database .
currently I use the code below to replace the word "of" from a string
let rawString = "I’m jealous of my parents. I’ll never have a kid as cool as theirs, one who is smart, has devilishly good looks, and knows all sorts of funny phrases."
var filtered = self.rawString.replacingOccurrences(of: "of", with: "")
what I want to do now is extend it to replace all preposition in a string.
What I was thinking of doing is creating a huge list of known prepositions like
let prepositions = ["in","through","after","under","beneath","before"......]
and then spliting the string by white space with
var WordList : [String] = filtered.components(separatedBy: " ")
and then looping through the wordlist to find a prepositional match and deleting it. Creating the list will be ugly and might not be efficient for my code.
What is the best way to detect and delete prepositions from a string?
Use NaturalLanguage:
import NaturalLanguage
let text = "The ripe taste of cheese improves with age."
let tagger = NLTagger(tagSchemes: [.lexicalClass])
tagger.string = text
let options: NLTagger.Options = [.omitPunctuation, .omitWhitespace]
var newSentence = [String]()
tagger.enumerateTags(in: text.startIndex..<text.endIndex, unit: .word, scheme: .lexicalClass, options: options) { tag, tokenRange in
guard let tag = tag, tag != .preposition else { return true }
newSentence.append("\(text[tokenRange])")
return true
}
print("Input: \(text)")
print("Output: \(newSentence.joined(separator: " "))")
This prints:
Input: The ripe taste of cheese improves with age.
Output: The ripe taste cheese improves age
Notice the two prepositions of and with are removed. My approach also removes the punctuation; you can adjust this with the .omitPunctuation option.
var newString = rawString
.split(separator: " ")
.filter{ !prepositions.contains(String($0))}
.joined(separator: " ")
I'm very, very new to Swift and admittedly struggling with some of its constructs. I have to work with a text file and do many manipulations - here's an example to illustrate the point:
let's say I have a text like this (multi line)
Mary had a little lamb
#name: a name
#summary: a paragraph of text
{{something}}
a whole bunch of multi-line text
x----------------x
I want to be able to do simple things like find the location of #name, then split it to get the name and so on. I've done this in javascript and it was pretty simple with the use of substr and the regex matches.
In swift, which is supposed to be swift and easy and what not, I'm finding this exceedingly confusing.
Can someone help with how one might do
Find the location of the start of a substring
Extract all text between from the end of a substring to the end of text
Sorry if this is trivial - but the Apple documentation feels very complicated, and lots of examples are years old. I can't also seem to find easy application of regex.
You can use string range(of: String) method to find the range of your string, get its upperBound and search for the end of the line from that position of the string:
Playground testing:
let sentence = """
Mary had a little lamb
#name: a name
#summary: a paragraph of text
{{something}}
a whole bunch of multi-line text
"""
if let start = sentence.range(of: "#name:")?.upperBound,
let end = sentence[start...].range(of: "\n")?.lowerBound {
let substring = sentence[start..<end]
print("name:", substring)
}
If you need to get the string from there to the end of the string you can use PartialRangeFrom:
if let start = sentence.range(of: "#summary:")?.upperBound {
let substring = sentence[start...]
print("summary:", substring)
}
If you find yourself using that a lot you can extend StringProtocol and create your own method:
extension StringProtocol {
func substring<S:StringProtocol,T:StringProtocol>(between start: S, and end: T, options: String.CompareOptions = []) -> SubSequence? {
guard
let lower = range(of: start, options: options)?.upperBound,
let upper = self[lower...].range(of: end, options: options)?.lowerBound
else { return nil }
return self[lower..<upper]
}
func substring<S:StringProtocol>(after string: S, options: String.CompareOptions = []) -> SubSequence? {
guard
let lower = range(of: string, options: options)?.upperBound else { return nil }
return self[lower...]
}
}
Usage:
let name = sentence.substring(between: "#name:", and: "\n") // " a name"
let sumary = sentence.substring(after: "#summary:") // " a paragraph of text\n\n{{something}}\n\na whole bunch of multi-line text"
You can use regular expressions as well:
let name = sentence.substring(between: "#\\w+:", and: "\\n", options: .regularExpression) // " a name"
You can do this with range() and distance():
let str = "Example string"
let range = str.range(of: "amp")!
print(str.distance(from: str.startIndex, to: range.lowerBound)) // 2
let lastStr = str[range.upperBound...]
print(lastStr) // "le string"
I'm bit confused by NSRegularExpression in swift, can any one help me?
task:1 given ("name","john","name of john")
then I should get ["name","john","name of john"]. Here I should avoid the brackets.
task:2 given ("name"," john","name of john")
then I should get ["name","john","name of john"]. Here I should avoid the brackets and extra spaces and finally get array of strings.
task:3 given key = value // comment
then I should get ["key","value","comment"]. Here I should get only strings in the line by avoiding = and //
I have tried below code for task 1 but not passed.
let string = "(name,john,string for user name)"
let pattern = "(?:\\w.*)"
do {
let regex = try NSRegularExpression(pattern: pattern, options: .caseInsensitive)
let matches = regex.matches(in: string, options: [], range: NSRange(location: 0, length: string.utf16.count))
for match in matches {
if let range = Range(match.range, in: string) {
let name = string[range]
print(name)
}
}
} catch {
print("Regex was bad!")
}
Thanks in advance.
RegEx in Swift
These posts might help you to explore regular expressions in swift:
Does a string match a pattern?
Swift extract regex matches
How can I use String slicing subscripts in Swift 4?
How to use regex with Swift?
Swift 3 - How do I extract captured groups in regular expressions?
How to group search regular expressions using swift?
Task 1 & 2
This expression might help you to match your desired outputs for both Task 1 and 2:
"(\s+)?([a-z\s]+?)(\s+)?"
Based on Rob's advice, you could much reduce the boundaries, such as the char list [a-z\s]. For example, here, we can also use:
"(\s+)?(.*?)(\s+)?"
or
"(\s+)?(.+?)(\s+)?"
to simply pass everything in between two " and/or space.
RegEx
If this wasn't your desired expression, you can modify/change your expressions in regex101.com.
RegEx Circuit
You can also visualize your expressions in jex.im:
JavaScript Demo
const regex = /"(\s+)?([a-z\s]+?)(\s+)?"/gm;
const str = `"name","john","name of john"
"name"," john","name of john"
" name "," john","name of john "
" name "," john"," name of john "`;
const subst = `\n$2`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Task 3
This expression might help you to design an expression for the third task:
(.*?)([a-z\s]+)(.*?)
const regex = /(.*?)([a-z\s]+)(.*?)/gm;
const str = `key = value // comment
key = value with some text // comment`;
const subst = `$2,`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Separate the string by non alpha numeric characters except white spaces. Then trim the elements with white spaces.
extension String {
func words() -> [String] {
return self.components(separatedBy: CharacterSet.alphanumerics.inverted.subtracting(.whitespaces))
.filter({ !$0.isEmpty })
.map({ $0.trimmingCharacters(in: .whitespaces) })
}
}
let string1 = "(name,john,string for user name)"
let string2 = "(name, john,name of john)"
let string3 = "key = value // comment"
print(string1.words())//["name", "john", "string for user name"]
print(string2.words())//["name", "john", "name of john"]
print(string3.words())//["key", "value", "comment"]
Here I have done with after understanding all of above comments.
let text = """
Capturing and non-capturing groups are somewhat advanced topics. You’ll encounter examples of capturing and non-capturing groups later on in the tutorial
"""
extension String {
func rex (_ expr : String)->[String] {
return try! NSRegularExpression(pattern: expr, options: [.caseInsensitive])
.matches(in: self, options: [], range: NSRange(location: 0, length: self.count))
.map {
String(self[Range($0.range, in: self)!])
}
}
}
let r = text.rex("(?:\\w+-\\w+)") // pass any rex
A single pattern, works for test:1...3, in Swift.
let string =
//"(name,john,string for user name)" //test:1
//#"("name"," john","name of john")"# //test:2
"key = value // comment" //test:3
let pattern = #"(?:\w+)(?:\s+\w+)*"# //Swift 5+ only
//let pattern = "(?:\\w+)(?:\\s+\\w+)*"
do {
let regex = try NSRegularExpression(pattern: pattern)
let matches = regex.matches(in: string, range: NSRange(0..<string.utf16.count))
let matchingWords = matches.map {
String(string[Range($0.range, in: string)!])
}
print(matchingWords) //(test:3)->["key", "value", "comment"]
} catch {
print("Regex was bad!")
}
Let’s consider:
let string = "(name,José,name is José)"
I’d suggest a regex that looks for strings where:
It’s the substring either after the ( at the start of the full string or after a comma, i.e., look behind assertion of (?<=^\(|,);
It’s the substring that does not contain , within it, i.e., [^,]+?;
It’s the substring that is terminated by either a comma or ) at the end of the full string, i.e., look ahead assertion of (?=,|\)$), and
If you want to have it skip white space before and after the substrings, throw in the \s*+, too.
Thus:
let pattern = #"(?<=^\(|,)\s*+([^,]+?)\s*+(?=,|\)$)"#
let regex = try! NSRegularExpression(pattern: pattern)
regex.enumerateMatches(in: string, range: NSRange(string.startIndex..., in: string)) { match, _, _ in
if let nsRange = match?.range(at: 1), let range = Range(nsRange, in: string) {
let substring = String(string[range])
// do something with `substring` here
}
}
Note, I’m using the Swift 5 extended string delimiters (starting with #" and ending with "#) so that I don’t have to escape my backslashes within the string. If you’re using Swift 4 or earlier, you’ll want to escape those back slashes:
let pattern = "(?<=^\\(|,)\\s*+([^,]+?)\\s*+(?=,|\\)$)"
When trying to remove the suffix from a filename, I'm only left with the suffix, which is exactly not what I want.
What (how many things) am I doing wrong here:
let myTextureAtlas = SKTextureAtlas(named: "demoArt")
let filename = (myTextureAtlas.textureNames.first?.characters.split{$0 == "."}.map(String.init)[1].replacingOccurrences(of: "\'", with: ""))! as String
print(filename)
This prints png which is the most dull part of the whole thing.
If by suffix you mean path extension, there is a method for this:
let filename = "demoArt.png"
let name = (filename as NSString).deletingPathExtension
// name - "demoArt"
Some people here seem to overlook that a filename can have multiple periods in the name and in that case only the last period separates the file extension. So this.is.a.valid.image.filename.jpg and stripping the extension should return this.is.a.valid.image.filename and not this (as two answers here would produce) or anything else in between. The regex answer works correctly but using a regex for that is a bit overkill (probably 10 times slower than using simple string processing). Here's a generic function that works for everyone:
func stripFileExtension ( _ filename: String ) -> String {
var components = filename.components(separatedBy: ".")
guard components.count > 1 else { return filename }
components.removeLast()
return components.joined(separator: ".")
}
print("1: \(stripFileExtension("foo"))")
print("2: \(stripFileExtension("foo.bar"))")
print("3: \(stripFileExtension("foo.bar.foobar"))")
Output:
foo
foo
foo.bar
You can also split the String using componentsSeparatedBy, like this:
let fileName = "demoArt.png"
var components = fileName.components(separatedBy: ".")
if components.count > 1 { // If there is a file extension
components.removeLast()
return components.joined(separator: ".")
} else {
return fileName
}
To clarify:
fileName.components(separatedBy: ".")
will return an array made up of "demoArt" and "png".
In iOS Array start with 0 and you want name of the file without extension, so you have split the string using ., now the name will store in first object and extension in the second one.
Simple Example
let fileName = "demoArt.png"
let name = fileName.characters.split(".").map(String.init).first
If you don't care what the extension is. This is a simple way.
let ss = filename.prefix(upTo: fileName.lastIndex { $0 == "." } ?? fileName.endIndex))
You may want to convert resulting substring to String after this. With String(ss)
#Confused with Swift 4 you can do this:
let fileName = "demoArt.png"
// or on your specific case:
// let fileName = myTextureAtlas.textureNames.first
let name = String(fileName.split(separator: ".").first!)
print(name)
Additionally you should also unwrapp first but I didn't want to complicate the sample code to solve your problem.
Btw, since I've also needed this recently, if you want to remove a specific suffix you know in advance, you can do something like this:
let fileName = "demoArt.png"
let fileNameExtension = ".png"
if fileName.hasSuffix(fileNameExtension) {
let name = fileName.prefix(fileName.count - fileNameExtension.count)
print(name)
}
How about using .dropLast(k) where k is the number of characters you drop from the suffix ?
Otherwise for removing extensions from path properly from filename, I insist you to use URL and .deletingPathExtension().lastPathComponent.
Maybe a bit overhead but at least it's a rock solid Apple API.
You can also use a Regexp to extract all the part before the last dot like that :
let fileName = "test.png"
let pattern = "^(.*)(\\.[a-zA-Z]+)$"
let regexp = try! NSRegularExpression(pattern: pattern, options: [])
let extractedName = regexp.stringByReplacingMatches(in: fileName, options: [], range: NSMakeRange(0, fileName.characters.count), withTemplate: "$1")
print(extractedName) //test
let mp3Files = ["alarm.mp3", "bubbles.mp3", "fanfare.mp3"]
let ringtonsArray = mp3Files.flatMap { $0.components(separatedBy: ".").first }
You can return a new string removing a definite number of characters from the end.
let fileName = "demoArt.png"
fileName.dropLast(4)
This code returns "demoArt"
One liner:
let stringWithSuffixDropped = fileName.split(separator: ".").dropLast().joined(separator: ".")
I have a string (HTML in this example case) which contains the same pattern for displaying the results of sports games. So, the HTML tags are known, but the values for each game are not.
In Perl, we can do this:
if ( $content =~ /\<\/a\>\<br\>(\d+)\<\/span\>\<br\>(\d+)\-(\d+).+\<\/a\>\<br\>(\d+)\<\/span\>\<br\>(\d+)\-(\d+)/) {
$visitingTeamScore = $1; // $1 is the 1st matched digit
$visitingTeamWins = $2; // $2 is the 2nd matched digit
$visitingTeamLosses = $3; // Etc
$homeTeamScore = $4;
$homeTeamWins = $5;
$homeTeamLosses = $6;
}
which returns the digits inside the parentheses, in this case 6 total integers of varying digit lengths. We can then assign those matches to variables.
From an answer in this question: Swift Get string between 2 strings in a string, I have the following Swift code:
extension String {
func sliceFrom(start: String, to: String) -> String? {
return (rangeOfString(start)?.endIndex).flatMap { sInd in
(rangeOfString(to, range: sInd..<endIndex)?.startIndex).map { eInd in
substringWithRange(sInd..<eInd)
}
}
}
}
let firstMatch = content?.sliceFrom("</a><br>", to: "</span>") // The first integer in the string
The problem comes in when getting the 4th integer which is also between </a\><br> and </span> so the resulting match will be the first digit again.
I can manually count the characters (which itself isn't a perfect science because the digits in each integer can differ) to do something ugly like:
let newRawHTML = content![content!.startIndex.advancedBy(15)...content!.startIndex.advancedBy(5)]
Another possibility is to remove anything matched already from the string, making it shorter for each subsequent search (which I'm not sure how to implement.) What's the way to do this? Is there any way in Swift to "pluck out" the matches?
The code you have shown as a Perl example, uses regular expression.
And in case the pattern is getting a little bit complex, you'd better use NSRegularExpression directly.
let pattern = "</a><br>(\\d+)</span><br>(\\d+)-(\\d+).+</a><br>(\\d+)</span><br>(\\d+)-(\\d+)"
let regex = try! NSRegularExpression(pattern: pattern, options: [])
if let match = regex.firstMatchInString(content, options: [], range: NSRange(0..<content.utf16.count)) {
let visitingTeamScore = (content as NSString).substringWithRange(match.rangeAtIndex(1))
let visitingTeamWins = (content as NSString).substringWithRange(match.rangeAtIndex(2))
let visitingTeamLosses = (content as NSString).substringWithRange(match.rangeAtIndex(3))
let homeTeamScore = (content as NSString).substringWithRange(match.rangeAtIndex(4))
let homeTeamWins = (content as NSString).substringWithRange(match.rangeAtIndex(5))
let homeTeamLosses = (content as NSString).substringWithRange(match.rangeAtIndex(6))
//...use the values
}