object-c review

//
//  main.m
//  cmdTry
//
//  Created by Calos Chen on 2017/8/21.
//  Copyright © 2017年 Calos Chen. All rights reserved.
//

#import <Foundation/Foundation.h>

@class Fraction;
@interface Fraction : NSObject
{
    int numberator;
    int denominator;
    NSString* name;
    double price;
    Fraction *myf;
}
@property double price;
-(void) print;
-(void) setNumberator: (int)n;
-(void) setName: (NSString*)na;
-(void) setInfo: (int) id name:(NSString*)name;

@end

@implementation Fraction

@synthesize price;

-(void) print
{
    NSLog(@"%i it is %@",numberator,name);
}
-(void) setNumberator:(int)n
{
    price=5;
    numberator=n;
}
-(void)setName:(NSString *)na{
    name=na;
}

-(void) setInfo:(int)id name:(NSString *)na{
    id=id;
    name=na;
}

@end

//---- program section ----

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        NSLog(@"Hello, World!");
        NSLog(@"who are you!");
    }

    NSLog(@"why is it");
    Fraction *myf= [[Fraction alloc] init];
    [myf setName:@"calos"];
    [myf print];

    int a1=5;
    float a2=3.23;
    double a3=3.44;
    char a4=‘c‘;
    int a5=(int)a2;
    for (int b=1; b<10;b++ ) {
        a5+=b;
    }
    myf.price=88;
    double b1=myf.price;
    BOOL isPrime=NO;
    NSLog(@"%i %f %e %c %i %c %g",a1,a2,a3,a4,a5,isPrime,b1);
    NSLog(@"end........");

    return 0;
}

//for today: 2017-08-21, I have read and practiced the first 153 pages of the object-c 2.0, now, I have known object-c classes and data types, and how to announce and implement the classes and class members, as well as functions in the class implementation. also property synthesize methods. loops.
//homework: implement a new class, and new interface and fill the class with members and all tangible members, then use all of them. @class declaration. So, write a console program with object-c.