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- www.ibm.com PHP OO Article This is a good read about PHP OO Good habits
- Encapsulate your code - having to change things in many places is a pain
- Write highly cohesive code by using strongly named grouping patterns - reuse is the goal
- Make it DRY - If you see it appear a second time then make it so it will only have to be changed in one place (Don't Repeat Yourself)
- No tight coupling
- Handle all possible errors
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