1 #import "HMViewController.h"
2
3 @interface HMViewController ()
4
5 @end
6
7 @implementation HMViewController
8
9 - (void)viewDidLoad
10 {
11 [super viewDidLoad];
12
13 // 块代码
14 NSArray *array = @[@(1), @(2), @(3), @(4), @(5)];
15
16 // 排序
17 array = [array sortedArrayUsingComparator:^NSComparisonResult(NSNumber *num1, NSNumber *num2) {
18
19 // 乱序=>一会升序，一会降序
20 // 随机
21 // arc4random_uniform(10) => 0~9之间的随机数
22 int seed = arc4random_uniform(2);
23 if (seed) {
24 return [num1 compare:num2];
25 } else {
26 return [num2 compare:num1];
27 }
28 }];
29
30 NSLog(@"%@", array);
31 }
32
33 - (void)sortWith:(NSArray *)array
34 {
35 // 排序
36 array = [array sortedArrayUsingComparator:^NSComparisonResult(NSNumber *num1, NSNumber *num2) {
37
38 /**
39 1 4 5 2
40 4 1 5 2
41 4 1 5 2
42 5 4 1 2
43 5 4 1 2
44 5 4 2 1
45 */
46 NSLog(@"%@ %@", num1, num2);
47
48 // 升序
49 // return [num1 compare:num2];
50 // 降序
51 return [num2 compare:num1];
52 }];
53
54 NSLog(@"%@", array);
55 }
56
57 - (void)arrayWith:(NSArray *)array
58 {
59 int i = 0;
60 for (NSNumber *num in array) {
61 NSLog(@"%@", num);
62
63 if (i == 1) {
64 break;
65 }
66 i++;
67 }
68
69 // 参数：对象，索引，是否中断
70 // 数组的块方法遍历的效率比for in高
71 [array enumerateObjectsUsingBlock:^(NSNumber *obj, NSUInteger idx, BOOL *stop) {
72 NSLog(@"%@", obj);
73
74 // idx == 1 退出循环
75 if (idx == 1) {
76 *stop = YES;
77 }
78 }];
79 }
80
81 @end
