[iOS]NSArray求最大值\最小值\平均值\和的快速方法

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];
    NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);