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