@property (nonatomic, retain) IBOutletCollection(UIButton) NSMutableArray *Buttons;

-(IBAction)toggleButtons:(id)sender
{
    NSUInteger Index = [button tag];
    [[Buttons objectAtIndex:Index] setHighlighted:YES];
}

[[Buttons objectAtIndex:3] setHighlighted:YES];

#import <UIKit/UIKit.h>

@interface SelectionViewController : UIViewController

@property (nonatomic, retain) IBOutletCollection(UIButton) NSMutableArray *Buttons;

- (IBAction)toggleButtons:(id)sender;

@end

#import "SelectionViewController.h"

@interface SelectionViewController ()

@end

@implementation SelectionViewController

@synthesize Buttons;


-(IBAction)toggleButtons:(id)sender
{
    UIButton *button = sender;
    NSUInteger Index = [button tag];
    [self performSelector:@selector(doHighlight:) withObject:sender afterDelay:0];

    [[Buttons objectAtIndex:Index] setHighlighted:YES];
}
- (void)doHighlight:(UIButton *)b {
    [b setHighlighted:YES];
}

-(IBAction)toggleButtons:(id)sender
{
    UIButton *button = sender;

    [button setHighlighted:YES];
}

-(IBAction)toggleButtons:(id)sender
{
    [myOutletButton setHighlighted:YES]; //Normal Outlet
}

for(id button in self.view.subviews)
{
    [button setHighlighted:YES];

}