当它尝试运行isKindofClass时，我得到了一个sigabort

Question

void PrintIntrospectionInfo()
{
// NSLog(@"Comes here1");

NSArray *myArray;
NSDate *aDate = [NSDate distantFuture];
NSValue *aValue = [NSNumber numberWithInt:5];
NSURL *urlObj = [NSURL URLWithString:@"http://www.yahoo.com"];
NSString *aString = @"string";
NSMutableString *mString = [NSMutableString stringWithFormat: @"Hello, %@", aString];
NSDictionary *stanford = [NSDictionary dictionaryWithObjectsAndKeys:@"http://www.stanford.edu", @"Stanford University", @"http://www.apple.com",@"Apple", @"http://cs193p.stanford.edu", @"CS193P",@"http://itunes.stanford.edu",@"Stanford on iTunesU",@"http://stanfordshop.com",@"Stanford Mall", nil];

myArray = [NSArray arrayWithObjects:aDate, aValue, aString,stanford,urlObj,mString, nil];

for(id someObject in myArray)
{
    NSLog(@"Comes here");

    if([someObject isKindofClass:[NSString string]])
    {

    }
}


}

Answer 1

做

for(id someObject in myArray)
{
    NSLog(@"Comes here");
    if([someObject isKindOfClass:[NSString class]])
    {

    }
}

而不是。注意，isKindOfClass的Of是大写的。我建议您使用NSObject*而不是id。然后，编译器会警告您isKindofClass方法不可用。通常，除非您使用的不是NSObject，否则不需要使用id：

for(NSObject* someObject in myArray)