Refactoring Improving the Design of Existing Code

Refactoring Improving the Design of Existing Code

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Refactoring,a First Example

• A poorly designed system is hard to change.Hard because it is hard to figure out where the changes are needed.
• When you find you have to add a feature to a program,and the program's code is not structured in a convenient way to add the feature,first refactor the program to make it easy to add the feature, then add the feature.
• The first step in refactoring is building a solid set of tests.
• Refactoring changes the programs in small steps. If you make a mistake, it is easy to find the bug.
• Good code should communicate what it is doing clearly, and variable names are a key to clear code
• Any fool can write code that a computer can understand. Good programmers write code that human can understand.

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