How to construct Regex pattern Swift

Question

I am trying to construct Regex but it doesn't work. Can anyone help?

I have a string, which I want to remove the following characters:

*_-+=#:><&[]\n

And instruct also to remove all text between (/ and )

Code is belkow:

if let regex = try? NSRegularExpression(pattern: "&[^*_-=;](\\)*;", options: .CaseInsensitive) {
let modString = regex.stringByReplacingMatchesInString(testString, options: .WithTransparentBounds, range: NSMakeRange(0, testString.characters.count), withTemplate: "")
print(modString)

}

By testing your regex in https://regex101.com, it failed because of the "-" character. Are you sure about your regex construction? — Larme, Feb 01 '16 at 16:36
@Larme No! That is why I came for help in Stack :).. There is something wrong in my regex. This is what I need to replace by whitespace *_-+=#:><&[] — Tal Zion, Feb 01 '16 at 16:38
Use Do-Try-Catch with an error variable instead of `try?` and a nice error message will appear explaining that the regex is invalid. Lesson of the day: do not ignore error messages. :) — Eric Aya, Feb 01 '16 at 16:39
Ok. It just that it wasn't clear since you mentioned that it didn't work on Swift 2.0. Indeed, with your question title, it seemed to be related to Swift. — Larme, Feb 01 '16 at 16:39

Wiktor Stribiżew · Accepted Answer · 2016-02-01T16:45:30.353

2

You can use

"\\(/[^)]*\\)|[*\r\n_+=#:><&\\[\\]-]"

See the regex demo

The \\(/[^)]*\\) alternative deals with all text between (/ and ) and [*_+=#:><&\\[\\]-] will match all the single characters you need to match.

Note that the hyphen in your regex must either be double-escaped, or placed at the start or end of the character class. Your regex did not work because it created an invalid range:

edited Feb 01 '16 at 16:45

answered Feb 01 '16 at 16:38

Wiktor Stribiżew

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Thanks. Forgot to include, my String has new lines \n which I also what to replace. Where would I add it? – Tal Zion Feb 01 '16 at 16:45
I updated the answer. Added `\r` and `\n` - just on case. – Wiktor Stribiżew Feb 01 '16 at 16:46
Amazing, thank you! All works perfect, only one that is still there is `–` How do I remove it as well? – Tal Zion Feb 01 '16 at 16:52
Do you mean a hyphen? It is at the end. If you need to match an em and en dash, just add like `"\\(/[^)]*\\)|[*\r\n_+=#:><&\\[\\]–—-]"` – Wiktor Stribiżew Feb 01 '16 at 16:58

How to construct Regex pattern Swift

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