OC语言 - 数组 | 数组排序 - 低头捡石頭

OC语言 - 数组 | 数组排序

数组

1 - OC 中的数组只能存放对象，不能存放非对象，如 int、结构体、枚举等

① NSArray

 1     NSArray * array01 = [NSArray arrayWithObjects:@"A",@"B",@"C", nil];
 2     NSLog(@"%@",array01);
 3     
 4     NSArray * array02 = [[NSArray alloc] initWithObjects:@"小",@"简直",@"了",@"白", nil];
 5     NSLog(@"%@",array02);
 6     
 7     NSLog(@"array02 count = %ld",[array02 count]);// 数组个数
 8     NSString * str01 = [array02 objectAtIndex:1]; // 按照下标获取数组元素
 9     NSLog(@"str01 = %@",str01);
10     
11     // 遍历数组
12     for (int i = 0; i< [array02 count]; i++) {
13 
14         NSString * str02 = [array02 objectAtIndex:i];
15         NSLog(@"%@",str02);
16     }

② NSMutableArray

// - Person.h

 1 #import <Foundation/Foundation.h>
 2 @interface Person : NSObject{
 3     NSString *_name;
 4     NSString *_sex;
 5     NSInteger _age;
 6 }
 7 
 8 // 输出性别、姓名、年龄
 9 - (void)sayHi;
10 
11 - (NSString *)name;
12 - (NSString *)sex;
13 - (NSInteger )age;
14 
15 - (id)initWithName:(NSString *)name sex:(NSString *)sex age:(NSInteger)age;
16 
17 
18 @end

// - Person.m

 1 #import "Person.h"
 2 @implementation Person
 3 - (void)sayHi{
 4     NSLog(@"姓名：%@,性别：%@,年龄：%ld",_name,_sex,_age);
 5 }
 6 
 7 - (id)initWithName:(NSString *)name
 8                sex:(NSString *)sex
 9                age:(NSInteger)age{
10     self = [super init];
11     if (self) {
12         _name = name;
13         _sex = sex;
14         _age = age;
15     }
16     return self;
17 }
18 
19 - (NSString *)description{
20     return [NSString stringWithFormat:@"%@,%@,%ld",_name,_sex,_age];
21 }
22 
23 @end

// - main.m

  1 #import <Foundation/Foundation.h>
  2 #import "Person.h"
  3 int main(int argc, const char * argv[]) {
  4 
  5     // 创建多个 Person 实例对象
  6     Person *person01 = [[Person alloc] initWithName:@"Liu" sex:@"m" age:15];
  7     Person *person02 = [[Person alloc] initWithName:@"Chen" sex:@"f" age:92];
  8     Person *person03 = [[Person alloc] initWithName:@"Zhang" sex:@"m" age:35];
  9     Person *person04 = [[Person alloc] initWithName:@"Li" sex:@"f" age:84];
 10     Person *person05 = [[Person alloc] initWithName:@"Wang" sex:@"m" age:51];
 11 
 12 
 13     // 同一对象可以在数组中存放多次
 14     NSArray *array03 = [[NSArray alloc] initWithObjects:person01,person02,person03,person04,person05,person02, person02,nil];
 15     NSLog(@"%@",array03);
 16     /* 输出
 17      (  "Liu,m,15",
 18         "Chen,f,92",
 19         "Zhang,m,35",
 20         "Li,f,84",
 21         "Wang,m,51",
 22         "Chen,f,92",
 23         "Chen,f,92"
 24      )
 25      */
 26 
 27     // 遍历 array03
 28     for (int i = 0; i< [array03 count]; i++) {
 29 
 30         Person * per = [array03 objectAtIndex:i];
 31         NSLog(@"%@",per);
 32     }
 33 
 34 
 35     // 数组可以存放不同的对象
 36     NSArray *array04 = [[NSArray alloc] initWithObjects:person01,person02,@"Fuck",person03,@"Be civilization",person04,person05, nil];
 37     // 是否是 Person 型对象
 38     for (int i = 0 ; i<[array04 count]; i++) {
 39         // id 类型
 40         id Obj = [array04 objectAtIndex:i];
 41 
 42         // isKindOfClass
 43         if ([Obj isKindOfClass:[Person class]]) {
 44 
 45             [Obj sayHi];
 46         }else{
 47 
 48             NSString *str = [array04 objectAtIndex:i];
 49             NSLog(@"非 Person 对象：%@",str);
 50         }
 51     }
 52 
 53 
 54     // containsObject：是否包含某对象
 55     BOOL res01 = [array04 containsObject:person04];
 56     NSLog(@"%@",res01 ? @"YES":@"NO");
 57 
 58 
 59     // indexOfObject：获取某对象在数组中的索引
 60     NSUInteger index = [array04 indexOfObject:person03];
 61     NSLog(@"%lu",index);
 62 
 63 
 64     // 获取数组的第一个/最后一个对象
 65     Person *firstPerson = [array04 firstObject];
 66     Person *lastPerson = [array04 lastObject];
 67     NSLog(@"数组的第一个对象:%@，数组的最后一个对象:%@",firstPerson,lastPerson);
 68 
 69 
 70     // 当内存不够的时候，系统自动会追加内存
 71     NSMutableArray *arr05 = [NSMutableArray arrayWithCapacity:1];
 72     [arr05 addObject:person01];
 73     [arr05 addObject:person02];
 74     [arr05 addObject:person03];
 75     [arr05 addObject:person04];
 76     [arr05 addObject:person05];
 77     NSLog(@"%@",arr05);
 78     [arr05 insertObject:@"Zhao" atIndex:3];// 插入
 79     NSLog(@"%@",arr05);
 80 
 81     // replaceObjectAtIndex：替换数组中的对象
 82     [arr05 replaceObjectAtIndex:3 withObject:@"Zhou"];
 83     NSLog(@"%@",arr05);
 84 
 85     // exchangeObjectAtIndex：交换两个下标的对象
 86     [arr05 exchangeObjectAtIndex:2 withObjectAtIndex:3];
 87     NSLog(@"%@",arr05);
 88 
 89     // 删除数组中的某个对象：重复的对象会全部移除
 90     [arr05 removeObject:person02];
 91     NSLog(@"%@",arr05);
 92 
 93     // 删除数组中某个位置的对象
 94     [arr05 removeObjectAtIndex:3];
 95     NSLog(@"%@",arr05);
 96 
 97     // 删除从某个范围的对象
 98     [arr05 removeObjectsInRange:NSMakeRange(1, 2)];
 99     NSLog(@"%@",arr05);
100 
101     // 删除数组中所有的对象
102     [arr05 removeAllObjects];
103     NSLog(@"%@",arr05);
104 
105     return 0;
106 }

注：for...in... 是不允许对可变容器的对象进行增删操作！若想要增删对象，可以考虑使用 for 循环

1     NSMutableArray *array99 = [[NSMutableArray alloc] initWithObjects:person01,person02,person03,person04,person05,nil];
2     for (Person *person in array99) {
3         if ([person age] < 24) {
4             [array99 removeObject:person]; // 程序 crash
5         }
6     }

数组排序

1 - block 排序

 1     NSArray *array = [NSArray arrayWithObjects:@"A",@"B",@"C", nil];
 2     
 3     // block 遍历：每遍历到一个元素，就会调用一次 block，并且把当前元素和索引当作参数传给 block
 4     [array enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
 5         
 6         NSLog(@"%lu - %@",(unsigned long)idx,obj);
 7         // 停止遍历
 8         if (idx == 1) {
 9             *stop = YES;
10         }
11     }];

我们可简单推测一下 block 遍历内部原理

 1     void (^myblock)(id,NSUInteger,BOOL *)= ^(id obj, NSUInteger idx, BOOL *stop){
 2         
 3         NSLog(@"%ld - %@", idx,obj);
 4         if (idx == 1) {
 5             *stop = YES;
 6         }
 7         
 8     };
 9     
10     
11     NSArray *arrayTest = [NSArray arrayWithObjects:@"A",@"B",@"C", nil];
12 
13     for (int i = 0; i < (int)array.count; i ++) {
14         BOOL isStop = NO;// 标记是否需要停止遍历
15         
16         id obj = arrayTest[i];// 获取元素
17         myblock(obj,i,&isStop);
18         if (isStop) {
19             break;
20         }
21         
22     }

2 - 使用自定义方法实现数组排序

// - Person.h

 1 #import <Foundation/Foundation.h>
 2 @interface Person : NSObject{
 3     NSString *_name;
 4     NSString *_sex;
 5     NSInteger _age;
 6 }
 7 
 8 - (NSString *)name;
 9 - (NSString *)sex;
10 - (NSInteger )age;
11 
12 - (id)initWithName:(NSString *)name sex:(NSString *)sex age:(NSInteger)age;
13 
14 // 按照年龄排序
15 - (NSComparisonResult)sortByAge:(Person *)person;
16 
17 // 按照姓名排序
18 - (NSComparisonResult)sortByName:(Person *)person;
19 
20 @end

// - Person.m

 1 #import "Person.h"
 2 @implementation Person
 3 
 4 
 5 - (id)initWithName:(NSString *)name
 6                sex:(NSString *)sex
 7                age:(NSInteger)age{
 8     self = [super init];
 9     if (self) {
10         _name = name;
11         _sex = sex;
12         _age = age;
13     }
14     return self;
15 }
16 
17 - (NSString *)description{
18     return [NSString stringWithFormat:@"%@,%@,%ld",_name,_sex,_age];
19 }
20 
21 - (NSString *)name{
22     return _name;
23 }
24 
25 - (NSString *)sex{
26     return _sex;
27 }
28 
29 - (NSInteger )age{
30     return _age;
31 }
32 
33 // 按照年龄排列
34 - (NSComparisonResult)sortByAge:(Person *)person{
35 
36 //    // 升序排列
37 //    if (_age < [person age]) {
38 //        return NSOrderedAscending;
39 //    }else if (_age > [person age]){
40 //        return NSOrderedDescending;
41 //    }
42 
43     // 降序排列
44     if ([person age] < _age) {
45         return NSOrderedAscending;
46     }else if ([person age]>_age){
47         return NSOrderedDescending;
48     }
49 
50     return NSOrderedSame;
51 }
52 
53 // 按照姓名排除
54 - (NSComparisonResult)sortByName:(Person *)person{
55 
56     // 升序
57     return [_name compare:[person name]];
58 
59     // 降序
60     // return [[person name] compare:_name];
61 
62 }
63 
64 
65 @end

// - main.m

 1 #import <Foundation/Foundation.h>
 2 #import "Person.h"
 3 int main(int argc, const char * argv[]) {
 4 
 5     // 方式一：系统方法，只限于字符串
 6     NSArray *array088 = [NSArray arrayWithObjects:@"Bruce",@"Jason",@"Hazell",@"Mark",@"Jicyy",@"Lucy",@"Rose",@"Solina", nil];
 7     NSArray *newArray088 = [array088 sortedArrayUsingSelector:@selector(compare:)];
 8     NSLog(@"compare：%@",newArray088);// (Bruce, Hazell, Jason, Jicyy, Lucy, Mark, Rose, Solina)
 9      
10     
11     // 方式二：自定义方法
12     Person *person01 = [[Person alloc] initWithName:@"Liu" sex:@"m" age:15];
13     Person *person02 = [[Person alloc] initWithName:@"Chen" sex:@"f" age:92];
14     Person *person03 = [[Person alloc] initWithName:@"Zhang" sex:@"m" age:35];
15     Person *person04 = [[Person alloc] initWithName:@"Li" sex:@"f" age:84];
16     Person *person05 = [[Person alloc] initWithName:@"Wang" sex:@"m" age:51];
17     // 把对象放进数组
18     NSArray *array05 = [NSArray arrayWithObjects:person01,person02,person03,person04,person05,nil];
19 
20     // 按照年龄排序：降序
21     NSArray *newArray04 = [array05 sortedArrayUsingSelector:@selector(sortByAge:)];
22     NSLog(@"sortByAge：%@",newArray04);// ("Chen,f,92",   "Li,f,84",   "Wang,m,51",   "Zhang,m,35",   "Liu,m,15")
23 
24     // 按照姓名排序：升序
25     NSArray *array06 = [array05  tor(sortByName:)];
26     NSLog(@"sortByName：%@",array06);//("Chen,f,92",    "Li,f,84",    "Liu,m,15",    "Wang,m,51",   "Zhang,m,35")
27 
28     return 0;
29 }

3 - 高级排序 sortedArrayUsingDescriptors

① 如果说有这样一种情况：Person 里有另外一个 Class 的变量，比如 Person 除了 name、age，还有一 Car 型实成员变量，而 Car 里还有 name 属性，那么在对 Person 实例对象进行排序时，要求：如果是同一辆车（以车名区分为例），则按照年龄进行排序；如果年龄相同，则按人名排序

② 代码实现

// - Car.h

1 #import <Foundation/Foundation.h>
2 @interface Car : NSObject
3 
4 @property(nonatomic,copy)NSString *name;// 车名
5 
6 +(Car *)initWithName:(NSString *)name;
7 
8 @end

// - Car.m

 1 #import "Car.h"
 2 @implementation Car
 3 
 4 +(Car *)initWithName:(NSString *)name{
 5 
 6     Car *car = [[Car alloc] init];
 7     car.name = name;
 8     return car;
 9 
10 }
11 
12 @end

// - Person.h

 1 #import <Foundation/Foundation.h>
 2 @class Car;
 3 @interface Person : NSObject
 4 
 5 @property(nonatomic,copy)NSString *name;
 6 @property(nonatomic,strong)Car *car;
 7 @property(nonatomic,assign)int age;
 8 
 9 +(Person*)personWithAge:(int)age withName:(NSString *)name withCar:(Car *)car;
10 
11 @end

// - Person.m

 1 #import "Person.h"
 2 #import "Car.h"
 3 @implementation Person
 4 
 5 +(Person*)personWithAge:(int)age withName:(NSString *)name withCar:(Car *)car{
 6 
 7     Person *person = [Person new];
 8     person.age = age;
 9     person.name = name;
10     person.car = car;
11 
12     return person;
13 
14 }
15 
16 -(NSString*)description{
17     
18     return [NSString stringWithFormat:@"age is %d , name is %@, car is %@",_age,_name,_car.name];
19 }
20 @end

// - main.m

 1 #import <Foundation/Foundation.h>
 2 #import "Person.h"
 3 #import "Car.h"
 4 int main(int argc, const char * argv[]) {
 5 
 6     // 搞 4 辆车
 7     Car *car1 = [Car initWithName:@"Audio"];
 8     Car *car2 = [Car initWithName:@"Rolls-Royce"];
 9     Car *car3 = [Car initWithName:@"BMW"];
10     Car *car4 = [Car initWithName:@"BYD"];
11 
12 
13     // 搞 5 个靓仔，人手一辆车
14     Person*p1 = [Person personWithAge:23 withName:@"Linda Lusardi" withCar:car3];
15     Person*p2 = [Person personWithAge:13 withName:@"Samantha Fox" withCar:car4];
16     Person*p3 = [Person personWithAge:13 withName:@"Melinda Messenger" withCar:car2];
17     Person*p4 = [Person personWithAge:22 withName:@"Keeley Hazell" withCar:car3];
18     Person*p5 = [Person personWithAge:30 withName:@"Joanne Guest" withCar:car1];
19    
20     NSArray *array = [NSArray arrayWithObjects:p1,p2,p3,p4,p5, nil];
21     
22     // 排序描述器
23     NSSortDescriptor *carNameDesc = [NSSortDescriptor sortDescriptorWithKey:@"car.name" ascending:YES];
24     NSSortDescriptor *personNameDesc = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES];
25     NSSortDescriptor *personAgeDesc = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:YES];
26 
27     // 把排序描述器放进数组，注意：放入的顺序就是你想要排序的顺序
28     // 这里是首先按照年龄排序、然后是车的名字、最后是按照人的名字
29     NSArray *descriptorArray = [NSArray arrayWithObjects:personAgeDesc,carNameDesc,personNameDesc, nil];
30     NSArray *sortedArray = [array sortedArrayUsingDescriptors: descriptorArray];
31     NSLog(@"%@",sortedArray);
32     return 0;
33 }