NSArray 初始化

//NSArray长度不可变所以初始化的时候就赋值,并且最后以nil结尾

//此外需要注意NSArray不能存放C语言的基础类型

NSObject*obj=[[NSObjectalloc]init];

NSArray*array1=[[NSArrayalloc]initWithObjects:@"abc",obj,@"cde",@"opq",nil];

NSArray*array2=[NSArrayarrayWithObjects:@"abc",obj,@"cde",@"opq",@25,nil];

NSLog(@"%zi",array1.count);//数组长度,结果:5

NSLog(@"%i",[array1containsObject:@"ce"]);//是否包含某个对象,结果:1

NSLog(@"%@",[array1lastObject]);//最后一个对象,结果:25

NSLog(@"%zi",[array1indexOfObject:@"abc"]);//对象所在的位置:0

Person*person1=[[Personalloc]initWithName:@"Kenshin"];

Person*person2=[[Personalloc]initWithName:@"Kaoru"];

Person*person3=[[Personalloc]initWithName:@"Rosa"];

NSArray*array2=[[NSArrayalloc]initWithObjects:person1,person2,person3,nil];

NSLog(@"%@",array2);