NSArray和NSMutableArray的详解

数组中不能存放基本数据类型，必须存放对象，因此如果要存放基本数据类型，先进行NSTimer封装

NSArray的用法：

第一、初始化

 

NSArray *firstArray=[[NSArray alloc] initWithObjects:@"one",@"two",@"three", nil];

        NSArray *secondArray=[NSArray arrayWithArray:firstArray];

第二、获取元素个数和访问

 

 

        NSLog(@"the number is %ld",[secondArray count]);

        NSLog(@"the value is %@",[secondArray objectAtIndex:2]);

第三、追加数据元素

 

 

        NSArray *thirdArray=[firstArray arrayByAddingObjectsFromArray:secondArray];

第四、数组转化为字符串

 

 

 

        NSString *str=[firstArray componentsJoinedByString:@".."];

        NSLog(@"the number is %@",str);

第五、判断是否包含字符串

 

 

        NSArray *firstArray=[[NSArray alloc] initWithObjects:@"one",@"two",@"three", nil];

        NSLog(@"has value %d",[firstArray containsObject:@"two"]);

        NSLog(@"has value %ld",[firstArray indexOfObject:@"two"]);

        NSLog(@"the last object is %@",[firstArray lastObject]);

NSMutalbeArray 的用法-

 

第一、基本的增删改

 

     NSMutableArray *mutableArr=[NSMutableArray arrayWithCapacity:4];

        [mutableArr addObject:@"hello"];

        [mutableArr addObject:@"hello"];

        [mutableArr addObject:@"hello"];



        [mutableArr addObject:@"richard"];

        [mutableArr insertObject:@"yang" atIndex:1];

        NSLog(@"%@",mutableArr);

        [mutableArr removeObject:@"hello"];

        [mutableArr removeObjectAtIndex:0];

        [mutableArr removeLastObject];

        NSLog(@"%@",mutableArr);

第二、替换操作

 

 

        [mutableArr replaceObjectAtIndex:0 withObject:@"kaixin"];

第三、遍历

 

 

        NSMutableArray *mutableArr=[NSMutableArray arrayWithCapacity:4];

        [mutableArr addObject:@"hello"];

        [mutableArr addObject:@"hello"];

        [mutableArr addObject:@"hello"];

        for(int index=0;index<[mutableArr count];index++)

        {

            NSLog(@"the val is %@",[mutableArr objectAtIndex:index]);

        }

        for(NSString *str in mutableArr)

        {

            NSLog(@"%@",str);

        }

        for (id str in mutableArr) {

            NSLog(@"%@",str);

        }