Question

Im new to iphone programming and im kinda stuck with my current project. I got a text file with a lot of data in it. Data is sorted like this:

51398030 10003254 80211593/94     1301281744 TOMTOM100  
51398030 10003254 80211593/94     1301281744 TOMTOM101  
51398030 10003254 80211593/94     1301281745 TOMTOM102  
51398030 10003254 80211593/94     1301281745 TOMTOM103  
51398033 10003254 80211595        1301281744 TOMTOM100  
51398033 10003254 80211595        1301281744 TOMTOM101  
51398033 10003254 80211595        1301281745 TOMTOM102  
51398033 10003254 80211595        1301281745 TOMTOM103  
51398029 10003254 80211597/98     1301281744 TOMTOM100  
51398029 10003254 80211597/98     1301281744 TOMTOM101  
51398029 10003254 80211597/98     1301281745 TOMTOM102  
51398029 10003254 80211597/98     1301281745 TOMTOM103

I already imported this txt file and created a NSMutableArray that contains each line as object. Now i have a textfield where the user can enter a number. the app should now look trough the text file and and sort out the lines containing this number.

I already looked at https://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/Strings/Articles/Scanners.html#//apple_ref/doc/uid/20000147-BCIEFGHC

but i dont know how to start.

This is how far i got:

    NSData *tmpData = [NSData dataWithContentsOfURL:[NSURL       URLWithString:trackTraceFileUrlName] ];
    NSLog(@"%@",trackTraceFileUrlName);
    //convert data to string 
    NSString *tmpString = [[NSString alloc] initWithData:tmpData              encoding:NSUTF8StringEncoding];
    NSArray *piecesArray = [tmpString componentsSeparatedByString:@"\n"];
    NSMutableArray *trackTraceContent = [NSMutableArray arrayWithArray:piecesArray];
    NSLog(@"*%@*",trackTraceContent);

Answer 1

Since you probably want to search over all the lines in the array, and assuming that you array just contains the strings as NSString objects:

NSArray *stringArray; // assuming that you already have these variables
NSString *numberEnteredByUser;
NSPredicate *pred = [NSPredicate predicateWithBlock:^(id obj, NSDictionary *bindings) {
    NSString *str = (NSString *)obj;
    return [str rangeOfString:numberEnteredByUser].location != NSNotFound;
}];
NSArray *results = [stringArray filteredArrayUsingPredicate:pred];

Of course, you can also create the target array without using NSPredicate, by just iterating over stringArray and adding the right objects to a NSMutableArray results.