You have a few options. It looks like the objects within the array have a description method that prints them the way you want to, so it may be as simple as using:
NSString *alertString = [path componentsJoinedByString:@" "];
If not, you could consider something like this:
NSMutableString *s = [NSMutableString string];
[path enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
[s appendString:@" "];
[s appendString:[obj someMethodThatFormatsTheObject]];
}];
NSString *alertString = [NSString stringWithString:s];
Or even:
NSMutableArray *a = [NSMutableArray array];
[path enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
[a addObject:[obj sometMethodThatFormatsTheObject]];
}];
NSString *alertString = [a componentsJoinedByString:@" "];