iOS NSArray NSMutableArray快速求总和、最大值、最小值、平均值的方法

    NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];

    CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];

    CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];

    CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];

    CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];

    NSInteger averageNum = [[array valueForKeyPath:@"@avg.intValue"] intValue];

对非0数组求平均值：

    NSMutableArray *heartB = [[NSMutableArray alloc] init];

    for(HWDHealthDataModel*item in array) {

        [heartA addObject:[NSNumber numberWithInt:item.heartRateNum]];

        if(item.heartRateNum>0) {

            [heartBaddObject:[NSNumber numberWithInt:item.heartRateNum]];

        }

    }

    NSIntegeraverageNum = [[heartBvalueForKeyPath:@"@avg.intValue"]intValue];