Untitled

Changing UIImageView with button
- (IBAction)Change:(id)sender {
   image.image = [UIImage imageNamed:@"car.png"];

}

- (IBAction)Change:(id)sender {

        if ([sender isSelected])
        {
          imageView.image = [UIImage imageNamed:@"car.png"];
          [sender setSelected:NO];
        }
        else
        {
          imageView.image = [UIImage imageNamed:@"bike.png"];
          [sender setSelected:YES];
        }
}

int counter;

- (IBAction)Change:(id)sender {
     counter++;
     imgView.image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.png",counter]];
}

BOOL isFirstImageShown=YES;

- (IBAction)Change:(id)sender {
   if(isFirstImageShown)
   {
      isFirstImageShown=NO;
      yourImageView.image = [UIImage imageNamed:@"yourSecondImage.png"];
   }
   else
   {
     isFirstImageShown=YES;
     yourImageView.image = [UIImage imageNamed:@"yourFirstImage.png"];
   }
}