iOS笔记系列目录

  • weak润饰的指针变量,在指向的内存地址销毁后,会在Runtime的机制下,主动置为nil。
  • _Unsafe_Unretain不会置为nil,容易呈现悬垂指针,产生解体。然而_Unsafe_Unretain比__weak效率高。
@interface MyClass()//@property (nonatomic, strong) NSMutableArray *array;//@property (nonatomic, weak) NSMutableArray *array;@property (nonatomic, unsafe_unretained) NSMutableArray *array;@end@implementation MyClass- (void)test {    self.array = @[@"1",@"2"].mutableCopy;    void (^block)(void) = ^ {        //应用unsafe_unretained上面这行会产生解体,self.array成了僵尸对象        NSLog(@"%@",self.array);        };    block();    NSLog(@"---");}