regular expressions replace in iOS

Question

I am going to need to replace a dirty string for a clean string:

-(void)setTheFilter:(NSString*)filter
{
    [filter retain];
    [_theFilter release];

    <PSEUDO CODE>
    tmp = preg_replace(@"/[0-9]/",@"",filter);
    <~PSEUDO CODE>

    _theFilter = tmp;
}

This should eliminate all numbers in the filter so that:

@"Import6652"
would yield @"Import"

How can I do it in iOS ?

Thanks!

Solution 1

NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:
                              @"([0-9]+)" options:0 error:nil];

[regex replaceMatchesInString:str options:0 range:NSMakeRange(0, [str length]) withTemplate:@""];

Swift

do {
    let regex = try NSRegularExpression(pattern: "([0-9]+)", options: NSRegularExpressionOptions.CaseInsensitive)
    regex.replaceMatchesInString(str, options: NSMatchingOptions.ReportProgress, range: NSRange(0,str.characters.count), withTemplate: "")
} catch {}

Solution 2

See the docs for NSRegularExpression

In particular the section titled Replacing Strings Using Regular Expressions

Solution 3

String replacing code using regex

Swift3

extension String {
    func replacing(pattern: String, withTemplate: String) throws -> String {
        let regex = try RegularExpression(pattern: pattern, options: .caseInsensitive)
        return regex.stringByReplacingMatches(in: self, options: [], range: NSRange(0..<self.utf16.count), withTemplate: withTemplate)
    }
}

use

var string: String = "Import6652"
do {
    let result = try string.replacing(pattern: "[\\d]+", withTemplate: "")
} catch {
    // error
}