How to validate a name(John D'Largy) in iOS Swift4.2?

Question

i tried all possibilities in stack-overflow (link1, link2) answers no use for me.

I am using following Regex to validate a first name. In online case (OnlineRegex) it is working fine but when i implemented in mobile it is not working.

Please help me

func isValidName() -> Bool {
    let RegEx = "^[a-zA-Z]+(([\\'\\,\\.\\-\\ ][a-zA-Z ])?[a-zA-Z]*)*$"
    let Test = NSPredicate(format:"SELF MATCHES %@", RegEx)
    return Test.evaluate(with: self)
}

i am calling above function as

let str = "John D'Largy"
        if str.isValidName(){
            print("Valid")
        }else{ print("Not valid")}

Output : "Valid"

Same function i am calling to validate my first text feild i am getting "Not valid"

if firstNameTxt.text.isValidName(){
            print("Valid")
        }else{ print("Not valid")}

i entered same text in mobile keyword

OutPut: "Not valid"

Did i missing something? or Should i have to change regex value?. Any suggestions.

Thanks in Advance.

Try `[a-zA-Z]+(?:[',.\\s-][a-zA-Z]+)*`. You do not need `^` and `$` — Wiktor Stribiżew, Apr 26 '19 at 09:04
@wiktor Stribiżew i used your line it is getting valid when i given text as string. When i'm entering the same text in mobile in textfeild it is showing not valid — chandra1234, Apr 26 '19 at 09:22
It is because you should only use this regex for final string validation. To make it work with partial string input add `?` after `[',.\\s-]`. — Wiktor Stribiżew, Apr 26 '19 at 09:56
i tried Both( 1). [a-zA-Z]+(?:[',.\\s-]?[a-zA-Z]+)* 2). [a-zA-Z]+(?:[',.\\s-][a-zA-Z]+)* ) no use — chandra1234, Apr 26 '19 at 11:01
I think the regex should allow an empty string. Try `(?:[a-zA-Z]+(?:[',.\\s-]?[a-zA-Z]+)*)?` — Wiktor Stribiżew, Apr 26 '19 at 12:31
Try `(?:[a-zA-Z]+(?:['‘’,.\\s-]?[a-zA-Z]+)*)?` (add the curly quotes). Or use the previous regex and set `textfield.smartQuotesType` property to `no` — Wiktor Stribiżew, Apr 26 '19 at 13:15
Awesome reply thank you it's working fine After adding this (?:[a-zA-Z]+(?:['‘’,.\\s-]?[a-zA-Z]+)*)? — chandra1234, Apr 26 '19 at 13:55

score 2 · Accepted Answer · edited Apr 29 '19 at 09:27

You may use

(?:[a-zA-Z]+(?:['‘’,.\\s-]?[a-zA-Z]+)*)?

The code you have already requires the full string match and you need no explicit anchors like ^ / \A and $ / \z.

Also, since the single quotation marks are automatically converted to curly quotes, you should either add them to the regex or turn off the behavior.

One of the most important things about thi regex is that it should be able to match partially correct string, thus all of the parts are optional (i.e. they can match 0 chars). It is wrapped with an optional non-capturing group ((?:...)?) that matches 1 or 0 occurrences.

Regex details

[a-zA-Z]+ - 1 or more letters
(?: - start of the inner non-capturing group:
- ['‘’,.\\s-]? - 1 or 0 whitespaces, single quotes, hyphens
- [a-zA-Z]+ - 1+ letters
)* - 0 or more repetitions.

Note: to match any Unbicode letter, use \\p{L} instead of [a-zA-Z].

Graph:

score 0 · Answer 2 · answered Apr 26 '19 at 09:21

0

See, I tried your code in the playground and changed the syntax a bit but not the logic

Below is the code snippet, try running that in your playground

    func isValidName(str: String) -> Bool {
       let RegEx = "^[a-zA-Z]+(([\\'\\,\\.\\-\\ ][a-zA-Z ])?[a-zA-Z]*)*$"
       let Test = NSPredicate(format:"SELF MATCHES %@", RegEx)
       return Test.evaluate(with: str)
    }

    func check(){
       let str = "John D'Largy"

       if isValidName(str: str){
           print("Valid")
       }else{
           print("Not valid")
       }
    }

check()

Hope it helps!

answered Apr 26 '19 at 09:21

Vijay Sanghavi

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Have your tried the way I showed? It is working fine in swift 4 and upwards. – Vijay Sanghavi Apr 26 '19 at 11:40
i tried your code it is working when static data given. When user is typing the name it is getting "Invalid" – chandra1234 Apr 26 '19 at 12:13

How to validate a name(John D'Largy) in iOS Swift4.2?

2 Answers2