Question

I want to do pretty much the same as in Excluding strings using regex but I want to do it iOS using Regex. So I basically I want to find matches in a string and then remove them from the string so if I have a string like this, Hello #world @something I want to find #world & @something and then remove them from the string so it just becomes Hello. I already have this expression that removes #world and something but not the @, #[\\p{Letter}]+|[^@]+$ I solved the @ problem by doing this

NSString *stringWithoutAt = [input stringByReplacingOccurrencesOfString:[NSString stringWithFormat:@"@%@",atString] withString:@""];
NSString *stringWithoutTag = [input stringByReplacingOccurrencesOfString:tagString withString:@""]; 

So for the first one I end up with Hello #world and the second one Hello @something. But is there a way of using Regex or something else to remove both the #world and the @something at the same time?

Answer 1

You can use regex in iPhone in two ways:-

1>Using RegExKitLIte as framework see the tutorial

2>Using NSRegularExpression & NSTextCheckingResult

NSStirng *string=@"Your String";
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"@[a-z]*#[a-z]*" options:NSRegularExpressionCaseInsensitive error:&error];
[regex enumerateMatchesInString:string options:0 range:NSMakeRange(0, [string length]) usingBlock:^(NSTextCheckingResult *match, NSMatchingFlags flags, BOOL *stop)
{
    // your statement if it matches
}];

Here any expression after@ and expression after # is being concatenated

and in the statement you can replace it by space to get your expression

if u simply want modified string do this :-

 NSString *modifiedString = [regex stringByReplacingMatchesInString:string options:0
range:NSMakeRange(0, [string length]) withTemplate:@"$2$1"];