4.1.1. Design purpose #

It is designed to be embedded in the application, so as to provide flexible extension and customization for the application.

4.1.2. Lua characteristics #

• Lightweight: it is written in standard C language and open in source code. After compilation, it is only more than 100 K, and can be easily embedded inother programs.

• Extensibility: Lua provides very easy-to-use extension interfaces and mechanisms: these functions are provided by the host language (usually C or C++) and can be used by Lua as if they were built-in functionality.

• Other features:

  • Support for process oriented (procedure-oriented) programming and functionalprogramming (functional programming);

  • Automatic memory management; only one common type of table (table) is provided, which can be used to implement arrays, hash tables, collections, and objects:

  • Language built-in pattern matching; closure; function can also be seen as a value; provides multithreading (collaborative processes, not threads supported by the operating system)

  • Closures and table can easily support some of the key mechanisms needed for object-oriented programming, such as data abstraction, virtual functions, inheritance and overloading.

4.1.3. Lua application scenario #

• Game development

• Stand-alone application script

• Web application script

• Extensions and database plug-ins such as MySQL Proxy and MySQL WorkBench

• Security systems, such as intrusion detection systems

4.1.4. The first Lua program #

Next, we use the Lua to output "Hello World!"

print("Hello World!")