Objective-C 程序设计（第六版）第九章习题答案

 1 //XYPoint类print方法
 2 
 3 
 4 - (void) print
 5 {
 6     NSLog(@" (%g , %g) ", x, y);
 7 }
 8 
 9 
10 //main函数部分
11 
12         id dataValue;
13         
14         XYPoint *x1 = [[XYPoint alloc] init];
15         
16         [x1 setX:12.01 andY:13];
17         dataValue = x1;
18         [dataValue print];

  1 #import <Foundation/Foundation.h>
  2 
  3 @interface Fraction : NSObject
  4 @property int numerator, denominator;
  5 
  6 - (void) print;
  7 //- (void) print: (BOOL) isReduce;
  8 - (void) setTo: (int) n  over: (int) d;
  9 //- (Fraction *) add: (Fraction *) f;
 10 - (id) addFrac: (id) f;
 11 //- (Fraction *) subtract: (Fraction *) f;
 12 //- (Fraction *) multiply: (Fraction *) f;
 13 //- (Fraction *) divide: (Fraction *) f;
 14 - (void) reduce;                  //约简
 15 - ( double) convertToNum;  //转换为双精度值
 16 
 17 @end
 18 
 19 
 20 #import "Fraction.h"
 21 
 22 @implementation Fraction
 23 @synthesize numerator, denominator;
 24 
 25 //@synthesize numerator,denominator;
 26 
 27 - (void) print
 28 {
 29     NSLog(@"%d / %d", numerator, denominator);
 30 }
 31 
 32 //- (void) print: (BOOL) isReduce  //BOOL参数 是否约简
 33 //{
 34 //    if (numerator % denominator == 0) {
 35 //        NSLog(@"%d",numerator/denominator);
 36 //    }else if (numerator > denominator){
 37 //        [self reduce];
 38 //        NSLog(@"%d %d/%d",numerator/denominator,numerator % denominator,denominator);
 39 //    }else if (isReduce) {
 40 //        [self reduce];
 41 //        NSLog(@"%d/%d",numerator,denominator);
 42 //    }else
 43 //        NSLog(@"%d/%d",numerator,denominator);
 44 //
 45 //}
 46 
 47 - (void) setTo: (int) n  over: (int) d
 48 {
 49     numerator = n;
 50     denominator = d;
 51 }
 52 
 53 - (id) addFrac: (id) f
 54 {
 55     Fraction *result = [[Fraction alloc] init];
 56     
 57     result.numerator = numerator * [f denominator] + denominator * [f numerator];
 58     result.denominator = denominator * [f denominator];
 59     
 60     return result;
 61 }
 62 
 63 //- (Fraction *) add: (Fraction *) f
 64 //{
 65 //    Fraction *result = [[Fraction alloc] init];
 66 //    
 67 //   result.numerator = numerator * f.denominator + denominator * f.numerator;
 68 //   result.denominator = denominator * f.denominator;
 69 //    
 70 //    [result reduce];
 71 //    return result;
 72 //}
 73 //
 74 //- (Fraction *) subtract: (Fraction *) f
 75 //{
 76 //    Fraction *result = [[Fraction alloc] init];
 77 //    
 78 //    result.numerator = numerator *f.denominator - denominator *f.numerator;
 79 //    result.denominator = denominator *f.denominator;
 80 //    
 81 //    [result reduce];
 82 //    return  result;
 83 //}
 84 //
 85 //- (Fraction *) multiply: (Fraction *) f
 86 //{
 87 //    Fraction *result = [[Fraction alloc] init];
 88 //    
 89 //    result.numerator = numerator *f.numerator;
 90 //    result.denominator = denominator *f.denominator;
 91 //    
 92 //    [result reduce];
 93 //    return result;
 94 //}
 95 //
 96 //- (Fraction *) divide: (Fraction *) f
 97 //{
 98 //    Fraction *result = [[Fraction alloc] init];
 99 //    
100 //    result.numerator = numerator *f.denominator;
101 //    result.denominator = denominator *f.numerator;
102 //    
103 //    [result reduce];
104 //    return result;
105 //}
106 
107 - (void) reduce
108 {
109     int u = numerator;
110     int v = denominator;
111     int temp;
112 
113     while (v != 0) {
114         temp = u % v;
115         u = v;
116         v = temp;
117     }
118     
119     numerator /= u;
120     denominator /= u;
121 }
122 
123 - ( double) convertToNum
124 {
125     if (denominator != 0) {
126         return (double) numerator / denominator;
127     }else
128         return NAN;
129         
130 }
131 
132 @end

 1 #import <Foundation/Foundation.h>
 2 
 3 @interface Complex : NSObject
 4 
 5 @property double real, imaginary;
 6 
 7 - (void) print;
 8 
 9 - (void) setReal: (double) a andImaginary: (double) b;
10 
11 //- (Complex *) add: (Complex *) f;
12 - (id) addComp: (id) c;
13 
14 @end
15 
16 
17 #import "Complex.h"
18 
19 @implementation Complex
20 
21 @synthesize real, imaginary;
22 
23 - (void) print
24 {
25     NSLog(@"%.1f + %.1fi", real, imaginary);
26 }
27 
28 - (void) setReal: (double) a andImaginary: (double) b
29 {
30     real = a;
31     imaginary = b;
32 }
33 
34 //- (Complex *) add: (Complex *) f
35 //{
36 //    Complex *result = [[Complex alloc] init];
37 //    
38 //    result.real = real + f.real;
39 //    result.imaginary = imaginary + f.imaginary;
40 //    
41 //    return result;
42 //}
43 
44 - (id) addComp: (id) c
45 {
46     Complex *result = [[Complex alloc] init];
47     
48     result.real = real + [c real];
49     result.imaginary = imaginary + [c imaginary];
50     
51     return result;
52 }
53 
54 @end

 1 #import <Foundation/Foundation.h>
 2 #import "Fraction.h"
 3 #import "Complex.h"
 4 
 5 int main(int argc, const char * argv[]) {
 6     @autoreleasepool {
 7 
 8         id dataValue1, dataValue2, result;
 9         
10         Fraction *f1 = [[Fraction alloc] init];
11         Fraction *f2 = [[Fraction alloc] init];
12         
13         [f1 setTo: 1 over: 2];
14         [f2 setTo: 1 over: 3];
15         
16         dataValue1 = f1;
17         dataValue2 = f2;
18         result = [dataValue1 addFrac:dataValue2];
19         [result print];
20         
21 //------------------------------------------------------
22         Complex *c1 = [[Complex alloc] init];
23         Complex *c2 = [[Complex alloc] init];
24         
25         [c1 setReal:12 andImaginary: 3];
26         [c2 setReal: 4 andImaginary: 5];
27         
28         dataValue1 = c1;
29         dataValue2 = c2;
30         result = [dataValue1 addComp:dataValue2];
31         [result print];
32 
33         }
34     return 0;
35 }

 1         Fraction *fraction = [[Fraction alloc] init];
 2         Complex *complex = [[Complex alloc] init];
 3         id number = [[Complex alloc] init];
 4         
 5         if ( [fraction isMemberOfClass:[Complex class]] == YES ) {
 6             NSLog(@"1");
 7         }
 8         if ( [complex isMemberOfClass:[NSObject class]] == YES) {
 9             NSLog(@"2");
10         }
11         if ( [complex isKindOfClass:[NSObject class]] == YES ) {
12             NSLog(@"3");
13         }
14         if ( [fraction isKindOfClass:[fraction class]] == YES ) {
15             NSLog(@"4");
16         }
17         if ([fraction respondsToSelector:@selector(print)] == YES ) {
18             NSLog(@"5");
19         }
20         if ( [complex respondsToSelector:@selector(print)] == YES ) {
21             NSLog(@"6");
22         }
23         if ( [Fraction instancesRespondToSelector:@selector(print)] == YES ) {
24             NSLog(@"7");
25         }
26         if ( [number respondsToSelector:@selector(print)] == YES ) {
27             NSLog(@"8");
28         }
29         if ( [number isKindOfClass:[Complex class]] == YES ) {
30             NSLog(@"9");
31         }
32         if ( [[number class] respondsToSelector:@selector(alloc)]  == YES ) {
33             NSLog(@"10");
34         }
35