Regex in objective C

Question

I want to extract only the names from the following string

bob!33@localhost @clement!17@localhost jack!03@localhost

and create an array [@"bob", @"clement", @"jack"].

I have tried NSString's componentsseparatedbystring: but it didn't work as expected. So I am planning to go for regEx.

1. How can I extract strings between ranges and add it to an array using regEx in objective C?
2. The initial string might contain more than 500 names, would it be a performance issue if I manipulate the string using regEx?

Answer 1

You can do it without regex as below (Assuming ! sign have uniform pattern in your all words),

NSString *names = @"bob!33@localhost @clement!17@localhost jack!03@localhost";
NSArray *namesarray = [names componentsSeparatedByString:@" "];
NSMutableArray *desiredArray = [[NSMutableArray alloc] initWithCapacity:0];
[namesarray enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
    NSRange rangeofsign = [(NSString*)obj rangeOfString:@"!"];
    NSString *extractedName = [(NSString*)obj substringToIndex:rangeofsign.location];
    [desiredArray addObject:extractedName];
}];
NSLog(@"%@",desiredArray);

output of above NSLog would be

(
    bob,
    "@clement",
    jack
)

If you still want to get rid of @ symbol in above string you can always replace special characters in any string, for that check this

If you need further help, you can always leave comment

Answer 2

NSMutableArray* nameArray = [[NSMutableArray alloc] init];
NSArray* youarArray = [yourString componentsSeparatedByString:@" "];
for(NSString * nString in youarArray) {
   NSArray* splitObj = [nString componentsSeparatedByString:@"!"];
   [nameArray addObject:[splitObj[0]]];
}    
NSLog(@"%@", nameArray);