string x = "alok b";
string y = "alok b";
string z = "alok";
//y += x.Replace(y, string.Empty);
z += " b";
Console.WriteLine(object.ReferenceEquals(x,y));
Console.WriteLine(object.ReferenceEquals(y, z));
第一行如何打印true和第二行false？
并更改为以下语句正在打印true。
Console.WriteLine(object.ReferenceEquals(y,string.Intern(z)));
答案 0 :(得分：1)
它被称为string interning。
答案 1 :(得分：0)
创建字符串时，它会创建一个对象（@interface ViewController ()
{
UIDocumentInteractionController * docController;
}
@end
- (void)sharePic:(UIImage *)image {
NSString *documentsDirectory = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"Image.ig"];
NSData *imageData = UIImageJPEGRepresentation(image, 0.8);
[imageData writeToFile:savedImagePath atomically:YES];
NSURL *imageUrl = [NSURL fileURLWithPath:savedImagePath];
docController = [UIDocumentInteractionController interactionControllerWithURL:imageUrl];
[docController retain];
docController.UTI = @"com.instagram.exclusivegram";
docController.delegate = self;
docController.annotation = [NSDictionary dictionaryWithObject:@"Caption Test" forKey:@"InstagramCaption"];
[docController presentOpenInMenuFromRect:CGRectZero inView:self.view animated:YES];
docController = nil;
}
）。
当您创建x时，您只需再次指向它，它指向同一个（拥有它）。
创建Z时，y完全创建一个新的，因此，它将与前一个内存中的地址不匹配。