Question

I have to do an animation with a label:
example:

If I have a label “WORLD” I want to do an animtion that first show “W” after 1 second “O”, and after 1 second “R”…ecc

Should I use a label or more label (one label for each letter)?

Answer 1

In this particular case you can simply add a timer and change the text in the label by adding one letter at a time.

In general for more complicated animations use more labels. You can animate the properties of a view so you must make each letter a view (label).

First you create the timer:

[NSTimer scheduledTimerWithTimeInterval:1.0
    target:self
    selector:@selector(targetMethod:)
    userInfo:nil
    repeats:YES];

and then you write the animating method similar to this:

-(void) targetMethod : (NSTimer*) timer {
    static int count = 0;
    NSString* letter = nil;
    switch(count) {
      case 0: letter = @"H"; break;
      case 1: letter = @"e"; break;
      case 2: letter = @"l"; break;
      case 3: letter = @"l"; break;
      case 4: letter = @"o";[timer invalidate]; break;
    }
    count++;
    label.text = [NSString stringWithFormat:"%@%@", label.text, letter];
}