objective-c第七章课后练习2

题：改变第七章例子中print方法，增加bool参数，判断如果是YES则对分数进行约简

 @interface Fraction : NSObject
 {
     //int num,den;

 }
 @property int num,den;//定义属性

 - (void) print:(BOOL) yesOrNo;//打印并判断是否约简分数
 //- (void) setN: (int) n;//设置n的值
 //- (void) setD: (int) d;//设置d的值
 //- (int) n;//返回n的值
 //- (int) d;//返回d的值
 - (void) setN: (int) n andSetD: (int) d;//2个参数的方法分别设置n和d的值
 - (double) convertToNum;
 - (void) add: (Fraction *) f;//分数相加方法
 - (void) reduce;//分数约简方法
 - (Fraction *) addFraction: (Fraction *) f;//加
 - (Fraction *) subFraction: (Fraction *) f;//减
 - (Fraction *) mulFraction: (Fraction *) f;//乘
 - (Fraction *) divFraction: (Fraction *) f;//除
 @end

 #import "Fraction.h"

 @implementation Fraction

 @synthesize num,den;//属性对应@property num,den

 - (void) print: (BOOL) yesOrNo//打印
 {
     if (yesOrNo == YES) {
         [self reduce];
     }
     NSLog(@"%i/%i",num,den);
 }
 //- (void) setN: (int) n//设置n的值
 //{
 //    num = n;
 //}
 //- (void) setD: (int) d//设置d的值
 //{
 //    den = d;
 //}
 //- (int) n//返回n的值
 //{
 //    return num;
 //}
 //- (int) d//返回d的值
 //{
 //    return den;
 //}

 - (void) setN: (int) n andSetD: (int) d
 {
     num = n;
     den = d;

 }
 - (double) convertToNum
 {
     if (den != )
     {
         return (double) num/den;

     }
     else
     {
         return NAN;

     }
 }

 - (void) add: (Fraction *) f
 {
     //分数相加:a/b + c/d = ((a*d) + (b*c)) / (b*d)

     num = num * f.den + den * f.num;
     den = den * f.den;

     [self reduce];
 }

 - (void) reduce
 {
     int u = num;
     int v = den;
     int temp;

     while (v != )
     {
         temp = u % v;
         u = v;
         v = temp;

     }
     num /= u;
     den /= u;
 }

 //加法
 - (Fraction *) addFraction: (Fraction *) f
 {
     Fraction *result = [[Fraction alloc]init];

     result.num = num * f.den + den * f.num;

     result.den = den * f.den;

     [result reduce];

     return result;

 }

 //减法
 - (Fraction *) subFraction: (Fraction *) f
 {
     Fraction *result = [[Fraction alloc]init];

     result.num = num * f.den - den * f.num;
     result.den = den * f.den;

     [result reduce];

     return result;

 }

 //乘法
 - (Fraction *) mulFraction: (Fraction *) f
 {
     Fraction *result = [[Fraction alloc]init];

     result.num = num * f.num;
     result.den = den * f.den;

     [result reduce];

     return result;
 }

 //除法
 - (Fraction *) divFraction: (Fraction *) f
 {
     //计算分数除以分数，第一个分数乘以第二个分数的倒数：1/2除以3/2 = 1/2 * 2/3
     Fraction *result = [[Fraction alloc]init];

     result.num = num * f.den;
     result.den = den * f.num;

     //[result reduce];

     return result;
 }
 @end

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

 int main(int argc, const char * argv[]) {
     @autoreleasepool {
         Fraction *myF = [[Fraction alloc]init];
         Fraction *myF_2 = [[Fraction alloc]init];
         Fraction *myResult;

         [myF setN: andSetD:];
         [myF_2 setN: andSetD:];

         myResult = [myF subFraction:myF_2];
         //[myResult print];

         myResult = [myF mulFraction:myF_2];
         //[myResult print];

         myResult = [myF divFraction:myF_2];

         int i;//定义整型变量i记录输入值
         BOOL b;//定义BOOL类型通过i值传递判断yes or no
         NSLog(@"Need to Simple? 1 or 0");
         //NSLog(@"ifReadOnly value: %@" ,ifReadOnly?@"YES":@"NO");
         scanf("%i",&i);
         b = i;//将i值赋给b
         [myResult print:b];

     }
     return ;
 }