First see JAVA-object-oriented-definition and method-primary evolution 07
Concept OOP
Process-oriented: step by step, linear thinking
Object-oriented: Things are gathered in categories: a classified thinking mode, suitable for multi-person cooperation
Nature
Organize code in the way of classes, and encapsulate data in the organization of objects
Three characteristics
Package
inherit
Polymorphism
Epistemological perspective
There are objects before classes, objects are concrete foods, and classes are abstractions of objects
Code operation perspective
Classes come first, then objects, classes are the template of objects
Method review
definition
- Modifier
- Return type
- break: jump out of switch, end the loop, and the difference between retrun
- Method name
- parameter list
- Exception thrown
Method call
- Static method
- Non-static method
- Formal and actual parameters
- Pass by value