Objective-c 數組對象 (NSArray 和 NSMutableArray)

一、NSArray是靜態數組，建立後數組內容及長度不能再修改。

執行個體:

//用arrayWithObjects初始化一個不可變的數組對象。//初始化的值之間使用逗號分開，以nil結束。NSArray6 *city = [NSArray arrayWithObjects:@"上海",@"廣州",@"重慶",nil];for(int i=0; i < [city count];i++){    NSLog(@"%@",[city objectAtIndex:i]);}

運行結果：

上海
廣州
重慶

NSArray常用方法：

+(id)arrayWithObjects:obj1,obj2,...nil             //建立一個新的數組，obj1,obj2,.., 以nil結束。-(BOOL)containsObject:obj                          //確定數組中是否包含對象obj-(NSUInterger)count                                //數組中元素的個數-(NSUInterger)indexOfObject:obj                    //第一個包含obj元素的索引號-(id)ObjectAtIndex:i                               //儲存在位置i的對象-(void)makeObjectsPerformSelector:(SEL)selector    //將selector提示的訊息發送給數組中的每一個元素-(NSArray*)sortedArrayUsingSelector:(SEL)selector  //根據selector提定的比較方法對數組進行排序-(BOOL)writeToFile:path atomically:(BOOL)flag      //將數組寫入指定的檔案中。如果flag為YES，則需要先建立一個臨時檔案

二、NSMutableArray是動態數組，可以動態增加數組中的元素，同樣NSMutableArray是NSArray的子類。
執行個體：

//用arrayWithCapacity建立一個長度為5的動態數組NSMutableArray *nsma = [MSMutableArray arrayWithCapacity:5];for(int i=0;i<=50;i++) {   if( i%3 == 0 ) {       [nsma addObject:[NSNumber numberWithInteger:i]];   //用addObject給數組nsma增加一個對象    }}//輸出數組中的元素for(int i=0;i<[nsma count];i++) {   NSLog(@"%li",(long)[[nsma objectAtIndex] integerValue]);}

數組排序例子：

student.h

#import <Foundation/Foundation.h>@interface Student: NSObject {  NSString: *name;  int age;}@property (copy,nonatomic) NSString* name;@property int age;-(void)print;-(NSComparisonResult)compareName:(id)element;@end

StudentTest.m

#import <Foundation/Foundation.h>#import "student.h"int main( int argc, const char* agrv[]) {  NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];  Student* stu1 = [[Student alloc] init];  Student* stu2 = [[Student alloc] init];  Student* stu3 = [[Student alloc] init];   [stu1 setName:@"Sam"];  [stu1 setAge:30];  [stu2 setName:@"Lee"];  [stu2 setAge:23];  [stu3 setName:@"Alex"];  [stu3 setAge:26];  NSMutableArray *students = [[NSMutableArray alloc] init];  [students addObject:stu1];  [students addObject:stu2];  [students addObject:stu3];   NSLog(@"排序前：");  for(int i=0; i<[students count];i++) {    Student *stu4 = [students objectAtIndex:i];    NSLog(@"Name:%@,Age:%i",[stu4 name],[stu4 age]);  }  [students sortUsingSelector:@selector(compareName:)];  NSLog(@"排序後：");  for( Student *stu4 in students ) {    NSLog(@"Name:%@,Age:%i", stu4.name, stu4.age);  }    [students release];  [stu1 release];  [sut2 release];  [stu3 release];  [pool drain];   return 0;}

結果：

排序前：Name:Sam,Age:30Name:Lee,Age:23Name:Alex,Age:26排序後：Name:Alex,Age:26Name:Lee,Age:23Name:Sam,Age:30

NSMutableArray常用方法：

+(id)array                                    //建立一個空數組+(id)arrayWithCapacity:size                   //建立一個容量為size的數組-(id)initWithCapacity:size                    //初始化一個新分配的數，指定容量為size-(void)addObject:obj                          //將obj增加到數組中-(void)insertObject:obj atIndex:i             //將obj插入資料的i元素-(void)replaceObjectAtIndex:i withObject:obj  //用obj替換第i個索引的對象-(void)removeObject:obj                       //從數組中刪除所有是obj的對象-(void)removeObjectAtIndex:i                  //從數組中刪除索引為i的對象-(void)sortUsingSelector:(SEL)selector        //用selector指示的比較方法進行排序