Question

输出应为

strString = değiştim
wkString  = NULL

但事实并非如此。为什么？

#import <Foundation/Foundation.h>

@interface learnARC : NSObject {
    NSString *strString, __weak *wkString;
}

@property (strong) NSString *strString;
@property (weak) NSString *wkString;

-(void) yaz;

@end

#import "learnARC.h"

@implementation learnARC

@synthesize wkString, strString;

-(void) yaz {
    NSString *anaString = @"anaString";
    strString = anaString;
    wkString = anaString;
    NSLog(@"\nstrString = %@\nwkString  = %@",strString,wkString);

    anaString = @"değiştim";
    NSLog(@"\nstrString = %@\nwkString  = %@",strString,wkString);
}

@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        learnARC *lrnarc = [[learnARC alloc]init];
        [lrnarc yaz];
    }
    return 0;
}

Answer 1

为什么？

~~因为您正在捕捉问题而不是您的班级名称......~~

严重的是，弱引用不应为NULL。您已为其指定了指针（指向字符串@"anaString"的指针）。由于字符串文字具有静态存储持续时间，因此在程序的生命周期内它们永远不会被释放。（我认为你可能会将变量与属性混淆？）

输出应该是什么？

1 个答案: