OC Exercises: Stock candlestick calculation

first, design a candlestick class

1) Lowest price (can read and write (Get,set))
2) Maximum price (read/write (Get,set))
3) Average price (read-only (get))

1, KLine.h

#import <Foundation/Foundation.h>

@interface kline:nsobject{
    @public
    float _highprice;
    float _lowprice;
    float _avgprice;
}

-(void) Sethighprice: (float) heighprice;
-(float) gethighprice;
-(void) Setlowprice: (float) lowprice;
-(float) getlowprice;
-(float) getavgprice;


@end

2, KLINE.M

#import "KLine.h"

@implementation KLine
-(void) Sethighprice: (float) heighprice{
    _highprice = Heighprice ;
    _avgprice = (_lowprice + _highprice)/2;
}
-(float) gethighprice{
    return _highprice;
}
-(void) Setlowprice: (float) lowprice{
    _lowprice = lowprice;
    _avgprice = (_lowprice + _highprice)/2;

}
-(float) getlowprice{
    return _lowprice;
}
-(float) getavgprice{
    //return (_lowprice + _highprice)/2;
    return _avgprice;
}
@end

3, Main.h:

#import <Foundation/Foundation.h>
#import "KLine.h"
int main (int argc, const char * argv[])
{

    @autoreleasepool {

        KLine *kline = [KLine new];
        [Kline sethighprice:30.0f];
        [Kline setlowprice:20.0f];
        float avg = [Kline Getavgprice];
        NSLog (@ "avg =%.2f", avg);

    }
    return 0;
}