NSArray NSDictionary一些用法

1     //从字符串分割到数组－ componentsSeparatedByString:
2     NSString *str = ［NSString alloc] initWithString:@"a,b,c,d"];
3     NSLog(@"str:%@",str);    
4     NSArray *array = [str componentsSeparatedByString:@","];
5     NSLog(@"array:%@",array);
6     [str release];

1     //从数组合并元素到字符串- componentsJoinedByString:
2     NSArray *array = ［NSArray alloc] initWithObjects:@"One",@"a",@"b",@"c",nil];
3     NSString *string = [array componentsJoinedByString:@","];
4     NSLog(@"string:%@",string);

1    //给数组分配容量
2    NSArray *array = [NSMutableArray arrayWithCapacity:20];

1    //在数组末尾添加对象

2    NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a",@"b",@"c",nil];
3    [array addObject:@"d"];
4    NSLog(@"array:%@",array);

 1    //删除数组中指定索引处对象
 2    NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a",@"b",@"c",nil];
 3    [array removeObjectAtIndex:1];
 4    NSLog(@"array:%@",array);

 1     //数组枚举
 2     NSMutableArray *array = [NSMutableArray arrayWithObjects: @"a",@"b",@"c",nil];
 3     NSEnumerator *enumerator;
 4     enumerator = [array objectEnumerator]; 
 5     id enum;
 6     while (enum = [enumerator nextObject]) {
 7         NSLog(@"enum:%@",enum);
 8      }

 1     //reverseObjectEnumerator;从后向前
 2     NSMutableArray *array = [NSMutableArray arrayWithObjects:@"a",@"b",@"c",nil];
 3     NSEnumerator *enumerator;
 4     enumerator = [array reverseObjectEnumerator];
 5     id object;
 6     while (object = [enumerator nextObject]) {
 7         NSLog(@"object:%@",object);
 8     }

1     //快速枚举
2     NSMutableArray *array = [NSMutableArray arrayWithObjects:
3     @"a",@"b",@"c",nil];
4     for(NSString *string in array)
5     {
6         NSLog(@"string:%@",string);
7     }

1    //创建字典
2    NSDictionary *dictionary = ［NSDictionary alloc] initWithObjectsAndKeys:@"a",@"b",@"c",nil];
3    NSString *string = [dictionary objectForKey:@"One"];
4    NSLog(@"string:%@",string);
5    NSLog(@"dictionary:%@",dictionary);
6    [dictionary release];

 1     //创建可变字典
 2     NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
 3     //添加字典
 4     [dictionary setObject:@"One" forKey:@"1"];
 5     [dictionary setObject:@"Two" forKey:@"2"];
 6     [dictionary setObject:@"Three" forKey:@"3"];
 7     [dictionary setObject:@"Four" forKey:@"4"];
 8     NSLog(@"dictionary:%@",dictionary);
 9 
10     //删除指定的字典
11     [dictionary removeObjectForKey:@"3"];
12     NSLog(@"dictionary:%@",dictionary);

 1     //NSDictionary 初始化
 2     NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"a", @"b", @"c", nil];
 3     //NSDictionary 个数
 4     NSLog(@"dictionary count: %ld", [dictionary count]);
 5 
 6     //NSDictionary 枚举keys/values 
 7     NSEnumerator *enum = [dictionary objectEnumerator];
 8     for (NSObject *enum in enum) {
 9         NSLog(@"enum: %@", enum);
10      }
11 
12 
13     NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"a",@"b",@"c", nil];
14     
15     //得到词典的数量
16     int count = [dictionary count];
17     NSLog(@"词典的数量为： %d",count);
18     
19     //得到词典中所有KEY值
20     NSEnumerator * enumeratorKey = [dictionary keyEnumerator];
21     
22     //快速枚举遍历所有KEY的值
23     for (NSObject *object in enumeratorKey) {
24         NSLog(@"遍历KEY的值: %@",object);
25     }
26     
27     //得到词典中所有Value值
28      NSEnumerator * enumeratorValue = [dictionary objectEnumerator];
29     
30     //快速枚举遍历所有Value的值
31     for (NSObject *object in enumeratorValue) {
32         NSLog(@"遍历Value的值: %@",object);
33     }
34     
35     //通过KEY找到value
36     NSObject *object = [dictionary objectForKey:@"a"];
37     
38     if (object != nil) {
39         NSLog(@"通过KEY找到的value是: %@",object);
40     }
41