How to make a Else If statement more suitable, Xcode 4 iOS

Question

I have a serious long else if statement which contains some links and some text. This is for Xcode 4, iOS 5 EDIT:

stationList = [[NSMutableArray alloc] init];
[stationList addObject:@"Q-dance Radio"];
[stationList addObject:@"The Voice"];
(ect ...)
[stationList sortUsingFunction:compareLetters context:nil];


[tableView deselectRowAtIndexPath:indexPath animated:YES];
    
    if ([[stationList objectAtIndex:indexPath.row] isEqual:@"Q-dance Radio"])
    {
        [player pause];
        NSString *u = @"LINK TO Q DANCE RADIO";
        NSURL *url = [NSURL URLWithString:u];
        player = [[AVPlayer alloc] initWithURL:url];
        [player play];
        
    }else if{
        [player pause];
        NSString *u = @"LINK TO THE VOICE";
        NSURL *url = [NSURL URLWithString:u];
        player = [[AVPlayer alloc] initWithURL:url];
        [player play];
        
    } (ect ...)

How can I make this better or make it find the pressed one faster, so it doesn't need to run though the whole list.

Answer 1

You could use an NSDictionary, and use the static strings as keys. I think you will get a good speedup from that. (The dictionary look-up probably hashes the input string that you use as a key.)

If you show more details, I can probably provide a more thorough answer. For example, you could even store the "do something here" code as a ^{} style block.

UPDATE I am at my computer now and can refer to some real code for you. This is based on something I have already done. YOur code may be modified this way:

xxxList = [[NSMutableArray alloc] init];
xxxListActionDictionary = [[NSMutableDictionary alloc] initWithCapacity:10];  // add this line
[xxxList addObject:@"TEXT HERE"];
[xxxListActionDictionary 
    setObject:
          [[^{
              // DO SOMETHING HERE. THIS IS A BLOCK. SOME CODE TO BE EXECUTED.
          } copy] autorelease]    // I don't think you need autorelease if you use ARC
    forKey:@"TEXT HERE"];   // TEXT HERE is the same text put into the xxxListArray

ect.

[tableView deselectRowAtIndexPath:indexPath animated:YES];

// Here is where it gets efficient.
// The next three lines of code replace the entire if-else if...
void (^action)(void) = [xxxActionDictionary objectForKey:[[xxxList objectAtIndex:indexPath.row]];  
if (action != nil) // you want to make sure the key is in the dictionary. may not be needed in your case.
    action();  // this executes the block

UPDATE

stationList = [[NSMutableArray alloc] init];

[stationList addObject:@"Q-dance Radio"];
[stationListDictionary setObject:@"http://whateverQDanceRadioIs.com/folder/..." forKey:@"Q-dance Radio"];

[stationList addObject:@"The Voice"];
[stationListDictionary setObject:@"http://whateverTheVoiceIs.com/folder/..." forKey:@"Q-dance Radio"];

(ect ...)


[tableView deselectRowAtIndexPath:indexPath animated:YES];


[player pause];
NSString *u = [stationListDictionary objectForKey[stationList objectAtIndex:indexPath.row]];
NSURL *url = [NSURL URLWithString:u];
player = [[AVPlayer alloc] initWithURL:url];
[player play];