PMOKVOAggregationOnSetOfObjects

main.m

#import <Foundation/Foundation.h>
#import "PMOLottoNumbers.h"

@interface PMOTransaction : NSObject

@property NSString *name;
@property NSNumber *amount;
@property NSDate *transactionDate;

@end

@implementation PMOTransaction

@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        
        PMOTransaction *transaction1 = [[PMOTransaction alloc] init];
        
        transaction1.name = @"Mark";
        transaction1.amount = @1000;
        transaction1.transactionDate = today;
        
        PMOTransaction *transaction2 = [[PMOTransaction alloc] init];
        
        transaction2.name = @"Mark";
        transaction2.amount = @500;
        transaction2.transactionDate = [today dateByAddingTimeInterval: -86400.0];
        
        PMOTransaction *transaction3 = [[PMOTransaction alloc] init];
        
        transaction3.name = @"Abella";
        transaction3.amount = @99999;
        transaction3.transactionDate = [today dateByAddingTimeInterval: 86400.0];
        
        NSArray *transactions = @[transaction1, transaction2, transaction3];
        
        NSNumber *maxAmount = [transactions valueForKeyPath:@"@max.amount"];
        NSNumber *minAmount = [transactions valueForKeyPath:@"@min.amount"];
        NSNumber *sumOfAmount = [transactions valueForKeyPath:@"@sum.amount"];
        NSNumber *avgOfAmount = [transactions valueForKeyPath:@"@avg.amount"];
        
        NSLog(@"\nminAmount: %@\nmaxAmount: %@\nsumOfAmount: %@\navgOfAmount: %@\n", minAmount, maxAmount, sumOfAmount, avgOfAmount);
        
        NSString *minName = [transactions valueForKeyPath:@"@min.name"];
        NSString *maxName = [transactions valueForKeyPath:@"@max.name"];
        NSString *countName = [transactions valueForKeyPath:@"@count.name"];
        
        NSLog(@"\nminName: %@\nmaxName: %@\ncountName: %@", minName, maxName, countName);
        
    }
    return 0;
}