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copied!<p>In addition to katzenhut's suggestion of manually calculating the average, you can use KVC collection operators, too, e.g.:</p> <pre><code>NSArray *array = @[@10, @25, @30]; NSNumber *average = [array valueForKeyPath:@"@avg.self"]; </code></pre> <p>Or, if dealing with objects, for example a "Product" model object with this interface:</p> <pre><code>@interface Product : NSObject @property (nonatomic, copy) NSString *name; @property (nonatomic) double price; - (id)initWithName:(NSString *)name price:(double)price; // the corresponding implementation should be obvious, so I'll not include it in this code snippet @end </code></pre> <p>You could then do:</p> <pre><code>NSMutableArray *products = [NSMutableArray array]; [products addObject:[[Product alloc] initWithName:@"item A" price:1010.0]]; [products addObject:[[Product alloc] initWithName:@"item B" price:1025.0]]; [products addObject:[[Product alloc] initWithName:@"item C" price:1030.0]]; NSNumber *average = [products valueForKeyPath:@"@avg.price"]; </code></pre> <hr> <p>If you want to take the results and populate a label with the results, you might do something like:</p> <pre><code>NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init]; formatter.numberStyle = NSNumberFormatterDecimalStyle; formatter.maximumFractionDigits = 2; // two decimal places? self.averageLabel.text = [formatter stringFromNumber:average]; </code></pre> <p>The advantage of <code>NSNumberFormatter</code> over <code>stringWithFormat</code> is that you have greater control over the string representation of the number, e.g. it can observe localization, employ thousandths separators, etc.</p>

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