不同國家姓名可能姓在前或是名在前, 利用以下 method 判斷.

if(ABPersonGetSortOrdering() == kABPersonCompositeNameFormatFirstNameFirst)
{
    return [NSString stringWithFormat:@"%@ %@", self.firstName, self.lastName];
}
else
{
    return [NSString stringWithFormat:@"%@, %@", self.lastName, self.firstName];
}

參考 MKBlog