5 Writing a Program

• prep code: a form of pseudocode, to help you focus on the logic without stressing about syntax. 一种伪代码
• test code: a class or methods that will test the real code and validate that it's doing the right thing. 测试代码
• real code: the actual implementation of the class. 真实代码

Extreme Programming（极限编程): * Write the test code first * Make small, but frequent, releases * Develop in iteration cycles.