I am trying to read the string from a Label and remove the last character form it.
This is how I am trying:
#IBAction func del(sender: UIButton) {
let str = telephone.text!;
let newstr = str.remove(at: str.index(before: str.endIndex))
telephone.text = newstr;
}
When I run, I get an error:
"String" does not have a member named "remove"
Can someone help me figure out the problem?
Just started learning swift :(
remove(at:) mutates the receiver which must therefore be a variable
string:
var str = telephone.text!
str.remove(at: str.index(before: str.endIndex))
telephone.text = str
Alternatively use substring(to:), which returns the new string
instead of modifying the receiver:
let str = telephone.text!
let newstr = str.substring(to: str.index(before: str.endIndex))
telephone.text = newstr
remove is defined as follows:
public mutating func remove(at i: String.Index) -> Character
See the mutating modifier? That means it mutates the instance on which the method is called. In your case, the instance is str, a constant. Since constants cannot be mutated, the code does not compile.
And since remove returns the removed character,
let newstr = str.remove(at: str.index(before: str.endIndex))
here newstr will not be storing the string with the last character removed.
You should rewrite the method like this:
telephone.text!.remove(at: telephone.text!.index(before: telephone.text!.endIndex))
You can use:
let idx = str.index(before: str.endIndex) // compute the index
let s = str.substring(to: idx) // get the substring
Related
I am trying to use an iOS app to dial a number. The problem is that the number is in the following format:
po placeAnnotation.mapItem.phoneNumber!
"+1 (832) 831-6486"
I want to get rid of some special characters and I want the following:
832-831-6486
I used the following code but it did not remove anything:
let charactersToRemove = CharacterSet(charactersIn: "()+-")
var telephone = placeAnnotation.mapItem.phoneNumber?.trimmingCharacters(in: charactersToRemove)
Any ideas?
placeAnnotation.mapItem.phoneNumber!.components(separatedBy: CharacterSet.decimalDigits.inverted)
.joined()
Here you go!
I tested and works well.
If you want something similar to CharacterSet with some flexibility, this should work:
let phoneNumber = "1 (832) 831-6486"
let charsToRemove: Set<Character> = Set("()+-".characters)
let newNumberCharacters = String(phoneNumber.characters.filter { !charsToRemove.contains($0) })
print(newNumberCharacters) //prints 1 832 8316486
I know the question is already answered, but to format phone numbers in any way one could use a custom formatter like below
class PhoneNumberFormatter:Formatter
{
var numberFormat:String = "(###) ### ####"
override func string(for obj: Any?) -> String? {
if let number = obj as? NSNumber
{
var input = number as Int64
var output = numberFormat
while output.characters.contains("#")
{
if let range = output.range(of: "#", options: .backwards)
{
output = output.replacingCharacters(in: range, with: "\(input % 10)")
input /= 10
}
else
{
output.replacingOccurrences(of: "#", with: "")
}
}
return output
}
return nil
}
func string(from number:NSNumber) -> String?
{
return string(for: number)
}
}
let phoneNumberFormatter = PhoneNumberFormatter()
//Digits will be filled backwards in place of hashes. It is easy change the custom formatter in anyway
phoneNumberFormatter.numberFormat = "###-##-##-##-##"
phoneNumberFormatter.string(from: 18063783889)
Swift 3
func removeSpecialCharsFromString(_ str: String) -> String {
struct Constants {
static let validChars = Set("1234567890-".characters)
}
return String(str.characters.filter { Constants.validChars.contains($0) })
}
To Use
let str : String = "+1 (832) 831-6486"
let newStr : String = self.removeSpecialCharsFromString(str)
print(newStr)
Note: you can add validChars which you want in string after operation perform.
If you have the number and special character in String format the use following code to remove special character
let numberWithSpecialChar = "1800-180-0000"
let actulNumber = numberWithSpecialChar.components(separatedBy: CharcterSet.decimalDigit.inverted).joined()
Otherwise, If you have the characters and special character in String format the use following code to remove special character
let charactersWithSpecialChar = "A man, a plan, a cat, a ham, a yak, a yam, a hat, a canal-Panama!"
let actulString = charactersWithSpecialChar.components(separatedBy: CharacterSet.letters.inverted).joined(separator: " ")
NSString *str = #"(123)-456-7890";
NSLog(#"String: %#", str);
// Create character set with specified characters
NSMutableCharacterSet *characterSet =
[NSMutableCharacterSet characterSetWithCharactersInString:#"()-"];
// Build array of components using specified characters as separtors
NSArray *arrayOfComponents = [str componentsSeparatedByCharactersInSet:characterSet];
// Create string from the array components
NSString *strOutput = [arrayOfComponents componentsJoinedByString:#""];
NSLog(#"New string: %#", strOutput);
I am very much new to swift language. I am performing some business logic which needs to take NSRange from given String.
Here is my requirement,
Given Amount = "144.44"
Need NSRange of only cent part i.e. after "."
Is there any API available for doing this?
You can do a regex-based search to find the range:
let str : NSString = "123.45"
let rng : NSRange = str.range("(?<=[.])\\d*$", options: .RegularExpressionSearch)
Regular expression "(?<=[.])\\d*$" means "zero or more digits following a dot character '.' via look-behind, all the way to the end of the string $."
If you want a substring from a given string you can use componentsSeparatedByString
Example :
var number: String = "144.44";
var numberresult= number.componentsSeparatedByString(".")
then you can get components as :
var num1: String = numberresult [0]
var num2: String = numberresult [1]
hope it help !!
Use rangeOfString and substringFromIndex:
let string = "123.45"
if let index = string.rangeOfString(".") {
let cents = string.substringFromIndex(index.endIndex)
print("\(cents)")
}
Another version that uses Swift Ranges, rather than NSRange
Define the function that returns an optional Range:
func centsRangeFromString(str: String) -> Range<String.Index>? {
let characters = str.characters
guard let dotIndex = characters.indexOf(".") else { return nil }
return Range(dotIndex.successor() ..< characters.endIndex)
}
Which you can test with:
let r = centsRangeFromString(str)
// I don't recommend force unwrapping here, but this is just an example.
let cents = str.substringWithRange(r!)
I have this kind of string: "POINT(101.650577657408 3.1653186153213)".
Anyone know how can I get the first and second value of POINT from this String?
You can easily spit the string using componentsSeparatedByString function.
let myStr = "POINT(101.650577657408 3.1653186153213)"
let characterSet = NSCharacterSet(charactersInString: "( )")
var splitString = myStr.componentsSeparatedByCharactersInSet(characterSet)
print(splitString[0])
print(splitString[1])
print(splitString[2])
The above only works if you have the complete one String.
Although the NSCharacterSet solution is correct but here is another solution using the most powerful regex.
var error: NSError?
// Initialise the regex for a float value
let regex: NSRegularExpression = NSRegularExpression(pattern: "(\\d*\\.\\d*)", options: NSRegularExpressionOptions.CaseInsensitive, error: &error)!
// Matches array contains all the match found for float in given string
let matches: NSArray = regex.matchesInString(str as String, options: NSMatchingOptions.ReportProgress, range: NSMakeRange(0, str.length))
// You can easily get all values by enumeration
for match in matches {
println(str.substringWithRange(match.range))
}
The benefit of this solution is it will scan all the float values and will also work in case of pattern got changed.
Try this, this will work for your string
let myStr = "POINT(101.650577657408 3.1653186153213)"
let strWithout_POINT_openingBrace = myStr.stringByReplacingOccurrencesOfString("POINT(", withString: "")//"101.650577657408 3.1653186153213)"
let strWithout_closingBrace = strWithout_POINT_openingBrace.stringByReplacingOccurrencesOfString(")", withString: "")//"101.650577657408 3.1653186153213"
//now you have only space between two values
//so split string by space
let arrStringValues = strWithout_closingBrace.componentsSeparatedByString(" ");//["101.650577657408","3.1653186153213"]
print(arrStringValues[0]);//first value "101.650577657408"
print(arrStringValues[1]);//second value "3.1653186153213"
I have a string:
let mystring = "key=value=value=value=value"
When i did:
let ar = mystring.componentsSeparatedByString("=")
i get:
["key", "value", "value", "value", "value"]
but i need do split only once, like componentsSeparatedByString("=", 1), to get:
["key", "value=value=value=value"]
With Swift 2.1, you can use the split function as follows to do what you want:
let result = string.characters.split("=", maxSplit: 1, allowEmptySlices: true)
Some example code to test this would be:
let string = "key=value=value=value=value"
let result = string.characters.split("=", maxSplit: 1, allowEmptySlices: true)
print(String(result[0])) // "key"
print(String(result[1])) // "value=value=value=value"
This should do the job
func extract(rawData: String) -> [String]? {
let elms = rawData.characters.split("=", maxSplit: 1).map { String($0) }
guard let
key = elms.first,
value = elms.last
where elms.count == 2 else { return nil }
return [key, value]
}
Example:
let rawData = "key=value=value=value=value"
extract(rawData) // > ["key", "value=value=value=value"]
Please note the extract function does an optional array of strings. Infact if the input string does not contain at least an = then nil is returned.
The code has been tested with the Swift 2.1 and Xcode Playground 7.1.1.
Hope this helps.
You're probably going to have to write your own custom code to do that, using either NSScanner or rangeofString:options:range:
EDIT:
Actually, it sounds like the Swift String class's split function, with its maxSplit parameter, will do what you need. Take a look at the link in Preston's answer.
let mystring = "key=value=value=value=value"
let result = split(mystring as String, { $0 == "=" }, maxSplit: 1, allowEmptySlices: true)
result should now be [key, value=value=value=value]
Thanks for answers, i found working solution for swift2:
let mystring = "key=value=value=value=value"
mystring.characters.split(1, allowEmptySlices: true, isSeparator: { $0 == "=" }).map(String.init)
Try this: (tested and working in playground)
var key = str.substringToIndex(str.rangeOfString("=")!.startIndex)
var value = str.substringFromIndex(str.rangeOfString("=")!.startIndex.advancedBy(1))
var resultingArray = [key, value]
I am trying to get the string from " src".."data-lazy-" in variable str, and it's work when i hard code it...
var str = "<h1 style=\"font-family: Helvetica\">Hello Pizza</h1><p>Tap the buttons above to see <strong>some cool stuff</strong> with <code>UIWebView</code><p><img src=\"https://apppie.files.wordpress.com/2014/09/photo-sep-14-7-40-59-pm_small1.jpg\" data-lazy-src=\"xxxxxxx\">"
str.rangeOfString(" src")?.startIndex
str.rangeOfString("data-lazy-")?.endIndex
let myNSString = str as NSString
myNSString.substringWithRange(NSRange(location: 150, length: 245-150))
Result: src=\"https://apppie.files.wordpress.com/2014/09/photo-sep-14-7-40-59-pm_small1.jpg\" data-lazy-
Here, i'm trying not to hard code it...
var str = "<h1 style=\"font-family: Helvetica\">Hello Pizza</h1><p>Tap the buttons above to see <strong>some cool stuff</strong> with <code>UIWebView</code><p><img src=\"https://apppie.files.wordpress.com/2014/09/photo-sep-14-7-40-59-pm_small1.jpg\" data-lazy-src=\"xxxxxxx\">"
str.rangeOfString(" src")?.startIndex
str.rangeOfString("data-lazy-")?.endIndex
let myNSString = str as NSString
let start = str.startIndex.toInt()
let end = str.endIndex.toInt()
myNSString.substringWithRange(NSRange(location: start, length: end - start))
The code above show error message 'String.index' does not have a member named 'toInt'
My question is how could i solve this problem?
Sorry, i am a fairly new to swift programming language.
Casting is not the problem.
The method substringWithRange() accepts an argument of Range - a Swift range - and a Range can be created with arguments of type String.Index. Thus use:
// I'm ignoring optionals; this code is unsafe and thus only an example
let beg = str.rangeOfString(" src")!
let end = str.rangeOfString("data-lazy-")!
str.substringWithRange(Range(start: beg.endIndex, end: end.startIndex))
Specifically:
15> var str = "abc src=def xyz"
str: String = "abc src=def xyz"
16> var si = str.rangeOfString("src=")!
si: Range<String.Index> = { ... }
17> var ei = str.rangeOfString(" xyz")!
ei: Range<String.Index> = { ... }
18> str.substringWithRange(Range (start: si.endIndex, end: ei.startIndex))
$R3: String = "def"
Don't be confused by the word 'Index' in 'String.Index' - this is not like 'i' in s[i]. A String.Index is an opaque data type; it behaves more like a pointer (in a C-like language). A String.Index has lots to account for in the Unicode world of Swift strings.