NSMutableArray

NSMutableArray 是一个可变数组,是NSArray的子类,但是不可以添加空值

创建NSMutableArray的方法

+(id)arrarWithCapacity:(NSInteger)numItems

-(id)initWithCapacity:(NSInteger)numItems

也可以用创建NSArray的方法创建NSMutableArray

当一个元素被加到集合中时，会执行一次retain操作；当一个元素从集合中移除时，会执行一次release操作，当集合被销毁时（dealloc），集合里面所有元素都执行一次release操作（这个原则同样适用于其它集合：NSDictionary\NSSet）

---

void arrayCreate(){

NSMutableArray *array=[NSMutableArray arrayWithObject：@“1”];

//Add elements

[array addObject:@”2”];

[array addObject:@”3”];

//removement

[array removeObject:@”2”];

[array removeLastObjects];

[array removeallobjects];

NSLog(@”%@”,array);

}

#pragma mark memory management

Student.h

@interface Student:NSObject

@property (nonatomic,assign) int age;

+(id)studentWithAge: (int) age;

@end

Student.m

@implemtation Student

+(id)studentWithAge: (int) age{

Student *stu= [[[Student alloc]init]autorelease];

stu.age=age;

return stu;

}

-(void)dealloc{

NSLog(@”age=%i is destroied”,_age);

[super dealloc];

}

 

@end

main.m

#import ”Student.h”

void arraymemory(){

NSMutableArray *arry=[NSMutableArray array];

Student *stu1=[Student studentWithAge:10];

Student *stu2=[Student studentWithAge:20];

[array addObject:stu1];

[array addObject:stu2];

NSLog(@”%zi”,[stu1 retainCount]);

//stu1,stu2 counter 2

[array removeObject:stu1];//stu1 counter1, stu2 counter 2

NSLog(@”%zi”,[stu1 retainCount]);

}

---

设置集合元素

-（void）setArray:(NSArry *)otherArray

添加一个元素

-（void）addobject:(id)anObject

添加otherArray的全部元素到集合中

-（void）addObjectsFromArray:(NSArray *)otherArray

插入一个对象,在Index地方插入一个对象

-（void）insertObjects:(id)anObject atIndex:(NSUInteger)index

在Indexs指定位置分别插入Objects中的元素

-（void）insertObjects;(NSArray *) objects atIndexs:(NSInsexSet *)indexs

---

#pragma mark replace elements

void arrayReplace(){

NSMutableArray *array=[NSMutableArray arrayWithObjects：@“1”,@”2”,@”3”,nil];

[array replaceObjectAtIndex:1 withObject:@”4”];//143
}

---

#pragma mark sort

void arrayort(){

NSMutableArray *array=[NSMutableArray arrayWithObjects：@“1”,@”3”,@”2”,nil];

[array sortUsingSelector:(compare:)];//因为是可变数组所以没有返回值

NSLog(@”%@”,array);

}