NSRegularExpressions - 過濾掉Xcode中的單詞

Question

我目前在教自己NSRegularExpressions以及如何過濾RSS源中的某些內容。特別是RSS feed的格式是「some text ::（可以有Re：這裏是答覆）some text :: some text」。我想刪除該Re：如果它存在。我知道應該有一種方法來做到這一點，而不是在我現有的那個中創建另一個NSRegularExpression。我沒有掌握所有的符號。我試圖使用？：取消Re：從捕獲，但我無法弄清楚如何。有人會介意爲我着想，並幫助我嗎？

NSRegularExpression *reg = [[NSRegularExpression alloc] initWithPattern:@".* :: ?:Re: (.*) :: .*" options:0 error:nil]; //The() creates a capture group and an array of ranges for reg 

    //Loop through every title of the items in channel 
    for (RSSItem *i in items) { 
     NSString *itemTitle = [i title]; 
     //find mittts 
     //Find matches in the title string. The range argument specifies how much of the title to search; in this case, all of it. 
     NSArray *matches = [reg matchesInString:itemTitle options:0 range:NSMakeRange(0, [itemTitle length])]; 

     //If there was a match... 
     if ([matches count] > 0) { 
      //Print the location of the match in the string and the string 
      NSTextCheckingResult *result = [matches objectAtIndex:0]; 

      NSRange r = [result range]; 

      NSLog(@"\nMatch at {%d, %d} for %@!\n", r.location, r.length, itemTitle); 


      NSLog(@"Range : %d",[result numberOfRanges]); 
      //One capture group, so two ranges, let's verify 
      if ([result numberOfRanges] == 2) { 
       //Pull out the 2nd range, which will be the capture group 
       NSRange r = [result rangeAtIndex:1]; 

       //Set the title of the item to the string within the capture group 
       [i setTitle:[itemTitle substringWithRange:r]]; 

       NSLog(@"%@", [itemTitle substringWithRange:r]); 
      } 
     } 
    } 

Answer 1

沒關係，找到它了。我需要（？：Re：）？以防止捕獲它。