How do i toggle UIButton using currentTitle in XCode - iphone

Question

To the point, i have 10 button and i write a number in Title inside every button, that is 0 to 9. My problem in here is, how do i toggle a button function, just say when i press a number 0, the value will show in showLabel.text is 0 and the button is in selected state but when i push it again, the number is gone in showLabel.text and the button is change back to normal state. I using this below code but it can't solve my problem. I mean, just say i selected number "1, 5, 7, 8" and i want to deselect number 5, using below code my showLabel will replace all number to none not to be "1, 7, 8". So i think this is not good idea using this code.
-(IBAction)numberBtn:(UIButton *)sender
{
UIButton *button = (UIButton *)sender;
[button setTitle:#"X" forState:UIControlStateSelected];
button.selected = !button.selected;
if (button.selected)
{
number = sender.currentTitle;
showLabel.text = [showLabel.text stringByAppendingFormat:number];
}
else
{
showLabel.text = [NSString stringWithFormat:#""];
}
}
Is there anyway to do that? Happy holiday.

Answer 1

Well. A think it will be good idea to make an array of 10 Boolean values and every time your button has been pressed - you just need to toggle corresponded value in your Boolean array and update your label using "for" loop:
for (int nn=0; nn<10; ++nn) if (boolVals[nn]) [myString appendFormat #"%d ", nn];

Answer 2

Do this instead:
- (IBAction)numberBtn:(UIButton *)sender {
sender.selected = !sender.selected;
if (sender.selected)
{
NSString *number = sender.currentTitle;
showLabel.text = [showLabel.text stringByAppendingString:number];
}
else
{
NSString *newString;
NSString *number = sender.currentTitle;
NSString *string = showLabel.text;
for (int i = 0; i<string.length; ++i) {
NSString *sub = [string substringWithRange:(NSRange){i, 1}];
if ([sub isEqualToString:number]) {
newString = [string substringToIndex:i];
newString = [newString stringByAppendingString:[string substringFromIndex:i+1]];
}
}
showLabel.text = newString;
}
[sender setTitle:#"X" forState:UIControlStateSelected];
}