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 }日志信息
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