Objective-C文法之NSArray和NSMutableArr

標籤：

 Objective-C的數組比C++，Java的數組強大在於，NSArray儲存的對象可以是不同的對象。但只能儲存對象，int ,char,double等基礎資料型別 (Elementary Data Type)不能直接儲存，需要通過轉換成對象才能加入數組。

1、NSArray 不可變數組

[array count] : 數組的長度。
[array objectAtIndex 0]: 傳入數組腳標的id 得到資料對象。
[arrayWithObjects; ...] :向數組對象初始化賦值。這裡可以寫任意對象的指標,結尾必須使用nil。

1.1、建立數組

1、建立數組

 

NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];

 

 

2、數組所包含對象個數

 

[self.dataArray count]

 

 

3、擷取指定索引處的對象

 

[self.dataArray objectAtIndex:2]

 

 

4、從一個數組拷貝資料到另一數組(可變數級)

 

//arrayWithArray:     //NSArray *array1 = [[NSArray alloc] init];     NSMutableArray *MutableArray = [[NSMutableArray alloc] init];     NSArray *array = [NSArray arrayWithObjects:                       @"a",@"b",@"c",nil];     NSLog(@"array:%@",array);     MutableArray = [NSMutableArray arrayWithArray:array];     NSLog(@"MutableArray:%@",MutableArray);     array1 = [NSArray arrayWithArray:array];     NSLog(@"array1:%@",array1);

 

 

5、COPY

 

NSMutableArray *newArray = [[NSMutableArray alloc] init];     NSArray *oldArray = [NSArray arrayWithObjects:                          @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];     NSLog(@"oldArray:%@",oldArray);     for(int i = 0; i < [oldArray count]; i++)     {                 obj = [[oldArray objectAtIndex:i] copy];         [newArray addObject: obj];     }     //         NSLog(@"newArray:%@", newArray);     [newArray release];

 

 

6、深COPY

 

//NSMutableArray *newArray = [[NSMutableArray alloc] init];     NSArray *oldArray = [NSArray arrayWithObjects:                          @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];         NSLog(@"oldArray:%@",oldArray);         newArray = (NSMutableArray*)CFPropertyListCreateDeepCopy(kCFAllocatorDefault, (CFPropertyListRef)oldArray, kCFPropertyListMutableContainers);     NSLog(@"newArray:%@", newArray);     [newArray release];

 

 

7、快速枚舉

//NSMutableArray *newArray = [[NSMutableArray alloc] init];     NSArray *oldArray = [NSArray arrayWithObjects:                          @"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",nil];         NSLog(@"oldArray:%@",oldArray);     for(id obj in oldArray)     {         [newArray addObject: obj];     }     //         NSLog(@"newArray:%@", newArray);     [newArray release];

8、切分數組

 

 

NSString *string = [[NSString alloc] initWithString:@"One,Two,Three,Four"]; NSLog(@"string:%@",string);     NSArray *array = [string componentsSeparatedByString:@","]; NSLog(@"array:%@",array); [string release];

 

 

9、從數組合并元素到字串

 

NSArray *array = [[NSArray alloc] initWithObjects:@"One",@"Two",@"Three",@"Four",nil];     NSString *string = [array componentsJoinedByString:@","];     NSLog(@"string:%@",string);

 

 

10、 給數組分配容量

 

array = [NSMutableArray arrayWithCapacity:20];

 

 

11、 在數組末尾添加對象

 

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"One",@"Two",@"Three",nil]; [array addObject:@"Four"]; NSLog(@"array:%@",array);

 

 

12、刪除數組中指定索引處對象

 

NSMutableArray *array = [NSMutableArray arrayWithObjects:@"One",@"Two",@"Three",nil]; [array removeObjectAtIndex:1];  NSLog(@"array:%@",array);

Objective-C文法之NSArray和NSMutableArr