Looping through objects in Objective-C

Question

I have a number of UIButtons and I'm setting a custom font on them programmatically, like this:

Button1.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
Button2.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
Button3.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
Button4.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
Button5.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
Button6.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];

This code is correct and it works, but it doesn't seem like the leanest way of writing it. Is there a way to loop through these elements instead?

I had imagined something like this:

for (int i = 1; i <= 5; i++) {
    Button(i).titleLabel.font = etc.. // How would I get the value of 'i'?
}

Or is this simply a bad idea?

Whether the buttons are in an array? Or individual instances? — Ilanchezhian
– Ilanchezhian, Commented Feb 13, 2012 at 9:53
how often do you need to do this (in how many different places)? You could add them to an NSdictionary and the loop through to pull them back out & change properties, but it is hardly worth if to replace 6 lines of code. — AnthonyBlake
– AnthonyBlake, Commented Feb 13, 2012 at 9:54
It would only make sense to loop through this if the buttons are in a known order in some sort of collection — nduplessis
– nduplessis, Commented Feb 13, 2012 at 9:55

Tharabas · Accepted Answer · 2012-02-13 09:55:10Z

5

You may use an NSArray to iterate over:

UIFont *font = [UIFont fontWithName:@"myCustomFont" size:16];
NSArray *buttons = [NSArray arrayWithObjects: Button1, Button2, Button3, 
                                              Button4, Button5, Button6, 
                                              nil];
for (UIButton *button in buttons) {
  button.titleLabel.font = font;
}

answered Feb 13, 2012 at 9:55

Tharabas

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2 Comments

Jezen Thomas Over a year ago

That's really neat. It's a shame I can only select one answer as correct! I'm choosing yours because it looks as though you were first.

Tharabas Over a year ago

Just remember not to forget the nil as last argument of [NSArray arrayWithObjects:] to avoid undefined behaviour. It's a so called variadic argument list, which need the nil to determine that there are no more arguments.

Artur Gurgul · Accepted Answer · 2012-02-13 10:13:02Z

2

you can do like this:

NSMutableArray *buttons = [NSMutableArray array];
[buttons addObject: Button1];
[buttons addObject: Button2];
[buttons addObject: Button3];
[buttons addObject: Button4];
[buttons addObject: Button5];
[buttons addObject: Button6];

for (UIButton *button in buttons) {
    button.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
}

or

for (int i=1;i<7;i++) {
    SEL selector = selectorFromString([NSString stringWithFormat:@"Button%d", i]);
    UIButton *button = [self performSelector:selector];
    button.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
}

edited Feb 13, 2012 at 10:13

answered Feb 13, 2012 at 9:55

Artur Gurgul

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1 Comment

Tharabas Over a year ago

You can not add an object to NSArray as it is immutable (can not be modified after init). But you could use NSMutableArray to achieve that.

TheAmateurProgrammer · Accepted Answer · 2012-02-13 09:55:24Z

1

Well, I guess you can put all of your buttons in an array, then fast enumerate through it.


NSArray *buttons; 
//Put all of your buttons inhere
for (UIButton *button in buttons)
{
    button.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
}

answered Feb 13, 2012 at 9:55

TheAmateurProgrammer

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Comments

Nick · Accepted Answer · 2014-03-20 21:05:01Z

0

How about this? currentView is the UIView that has all the buttons in it.

NSArray* buttonsArray = currentView.subviews;

for((UIButton*) button in buttonsArray)
{
     button.titleLabel.font = [UIFont fontWithName:@"myCustomFont" size:16];
}

answered Mar 20, 2014 at 21:05

Nick

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