Ray's playground

摘要： You can declare a variable or a function in many different places,but there must be only one definition in C and C++ (this issometimes called the ODR: one-definition rule). 阅读全文

摘要： To archive objects other than those listed, you must tell the system how to archive, orencode, your objects, and also how to unarchive, or decode, them.This is done by addingencodeWithCoder: and initW... 阅读全文

摘要： The Foundation classes implement methods known as copy and mutableCopy that youcan use to create a copy of an object.This is done by implementing a method in conformancewith the <NSCopying> prot... 阅读全文

摘要： A file or directory is uniquely identified to NSFileManager using a pathname to the file.Apathname is an NSString object that can either be a relative or full pathname.A relativepathname is one that i... 阅读全文