objective-c 函数参数 传地址 传指针 指向指针的指针

传值和传址的区别，在参数get set  微妙区别  

#import "ViewController.h"

@interface ViewController ()

{

    NSMutableArray *_array;

   NSMutableArray *nextArray;

   NSData *mydata;

}

    

    

    

    

@end

@implementation ViewController

@synthesize array=_array;

- (void)viewDidLoad

{

    [superviewDidLoad];

    _array = [[NSMutableArrayalloc] initWithCapacity:4];

    

    [_array addObject:@"000"];

    nextArray = [[NSMutableArrayalloc] initWithCapacity:4];

    [nextArrayaddObject:@"002"];

    NSLog(@"_array%@",_array);

    NSLog(@"_array%p",_array);

    NSLog(@"nextArray%@",nextArray);

    NSLog(@"nextArray%p",nextArray);

    [selffoo:&_array];

    NSLog(@"_array%@",_array);

    NSLog(@"_array%p",_array);

}

-(void)foo:(NSMutableArray *__strong *) arraypointer  

//__strong：处理错误：Passing address of non-local object to __autoreleasing parameter for write-back

{

    *arraypointer =nextArray;

}

- (void)didReceiveMemoryWarning

{

    [superdidReceiveMemoryWarning];

    // Dispose of any resources that can be recreated.

}