比较 NSURL
NSString *urlString = @"https://www.stackoverflow.com";
NSURL *myUrl = [NSURL URLWithString: urlString];
NSURL *myUrl2 = [NSURL URLWithString: urlString];
if ([myUrl isEqual:myUrl2]) return YES;
NSString *urlString = @"https://www.stackoverflow.com";
NSURL *myUrl = [NSURL URLWithString: urlString];
NSURL *myUrl2 = [NSURL URLWithString: urlString];
if ([myUrl isEqual:myUrl2]) return YES;