``````<span style="font-size:18px;">                                  <span style="color:#FF6666;">main.m</span>                             </span>
<span style="font-size:18px;">#import <Foundation/Foundation.h>
#import "Person.h"
#import "Fraction.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {

Fraction *num = [[Fraction alloc] init];
[num print]; //打印初始化的值 3/5
Fraction *num1 = [Fraction fractionWithNumerator:24 denominator:36];
[num1 print]; //打印便利构造器值 24/36
[num1 reductionOfFraction];
[num1 print]; // 24/36 约分后 2/3

Fraction *num2 = [Fraction fractionWithNumerator:9 denominator:12];
Fraction *result1 = [Fraction addWitfAFraction:num1 bFraction:num2];// 加   24/36 + 2/3
[result1 print];
Fraction *result2 = [Fraction minusWitfAFraction:num1 bFraction:num2];// 减
[result2 print];
Fraction *result3 = [Fraction timeWitfAFraction:num1 bFraction:num2]; // 乘
[result3 print];
Fraction *result4 = [Fraction divideWitfAFraction:num1 bFraction:num2]; // 除
[result4 print];

}
return 0;
}
</span>``````

``````<span style="color:#FF6666;">                                 Fraction.h</span>
#import <Foundation/Foundation.h>

@interface Fraction : NSObject {
NSInteger _numerator;//分子
NSInteger _denominator;//分母
}
//自定义初始化方法
- (id)initWithNumerator:(NSInteger)aNumerator;
//便利构造器

//setter和getter
- (void)setNumerator:(NSInteger)aNumerator;
- (NSInteger)numerator;
- (NSInteger)denominator;

//最大公约数:辗转相除法
- (NSInteger)greatestCommonDivisorWithOneNumber:(NSInteger)oneNumber anotherNumber:(NSInteger)anotherNumber;
//约分
- (void)reductionOfFraction;
//打印
- (void)print;
//加
+ (Fraction *)addWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction;
//减
+ (Fraction *)minusWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction;
//乘
+ (Fraction *)timeWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction;
//除
+ (Fraction *)divideWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction;
@end
``````

``````<span style="color:#FF6666;">                                  Fraction.m</span>
#import "Fraction.h"

@implementation Fraction
- (instancetype)init
{
self = [super init];
if (self) {
_numerator = 3;
_denominator = 5;
}
return self;
}
//自定义初始化方法
- (id)initWithNumerator:(NSInteger)aNumerator {
self = [super init];
if (self) {
_numerator = aNumerator;
}
return self;
}
self = [super init];
if (self) {
_numerator = aNumerator;
}
return self;
}

//便利构造器
Fraction *fraction = [[Fraction alloc] init];
[fraction setNumerator:aNumerator];
return fraction;
}

//setter和getter
- (void)setNumerator:(NSInteger)aNumerator {
_numerator = aNumerator;
}
- (NSInteger)numerator {
return _numerator;
}
}
- (NSInteger)denominator {
return _denominator;
}

//最大公约数:辗转相除法
- (NSInteger)greatestCommonDivisorWithOneNumber:(NSInteger)oneNumber anotherNumber:(NSInteger)anotherNumber {
while (anotherNumber != 0) {
NSInteger temp = oneNumber % anotherNumber;
oneNumber = anotherNumber;
anotherNumber = temp;
}
return oneNumber;
}
//约分
- (void)reductionOfFraction {
NSInteger temp = [self greatestCommonDivisorWithOneNumber:_numerator anotherNumber:_denominator];
//self即可代指类, 也可代指对象, 谁调用就代表谁.
_numerator /= temp;
_denominator /= temp;
}
//打印
- (void)print {
NSLog(@"分数: %ld/%ld",_numerator, _denominator);
}
//加
+ (Fraction *)addWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction {
Fraction *result = [[Fraction alloc] init];
result.denominator = aFraction.denominator * bFraction.denominator;
result.numerator = aFraction.numerator * bFraction.denominator + bFraction.numerator * aFraction.denominator;
[result reductionOfFraction];//加完后整体约分
return result;
}
//减
+ (Fraction *)minusWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction {
Fraction *result = [[Fraction alloc] init];
result.denominator = aFraction.denominator * bFraction.denominator;
result.numerator = aFraction.numerator * bFraction.denominator - bFraction.numerator * aFraction.denominator;
[result reductionOfFraction];
return result;
}
//乘
+ (Fraction *)timeWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction{
Fraction *result  = [[Fraction alloc] init];
result.denominator = aFraction.denominator * bFraction.denominator;
result.numerator = aFraction.numerator * bFraction.numerator;
[result reductionOfFraction];
return result;
}
//除
+ (Fraction *)divideWitfAFraction:(Fraction *)aFraction bFraction:(Fraction *)bFraction {
Fraction *result = [[Fraction alloc] init];
result.denominator = aFraction.denominator * bFraction.numerator;
result.numerator = aFraction.numerator * bFraction.denominator;
[result reductionOfFraction];
return  result;
}
@end
``````