Use regular expression to find/replace substring in NSString

NSString *string = @"123 &1245; Ross Test 12";NSError *error = nil;NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"&[^;]*;" options:NSRegularExpressionCaseInsensitive error:&error];NSString *modifiedString = [regex stringByReplacingMatchesInString:string options:0 range:NSMakeRange(0, [string length]) withTemplate:@""];NSLog(@"%@", modifiedString);

String replacing code using regex in String extension

Objective-C

@implementation NSString(RegularExpression)- (NSString *)replacingWithPattern:(NSString *)pattern withTemplate:(NSString *)withTemplate error:(NSError **)error {    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:pattern                                                                           options:NSRegularExpressionCaseInsensitive                                                                             error:error];    return [regex stringByReplacingMatchesInString:self                                           options:0                                             range:NSMakeRange(0, self.length)                                      withTemplate:withTemplate];}@end

resolve

NSString *string = @"123 &1245; Ross Test  12";// remove all matches stringNSString *result = [string replacingWithPattern:@"&[\\d]+?;" withTemplate:@"" error:nil];// result = "123  Ross Test  12"

or more

NSString *string = @"123 +   456";// swap numberNSString *result = [string replacingWithPattern:@"([\\d]+)[ \\+]+([\\d]+)" withTemplate:@"$2 + $1" error:nil];// result = 456 + 123

Swift2

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

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 = "1!I 2\"want 3#to 4$remove 5%all 6&digit and a char right after 7'from 8(string"do {    let result = try string.replacing("[\\d]+.", withTemplate: "")} catch {    // error}// result = "I want to remove all digit and a char right after from string"