Revision

1. Keywords

2. Classes and Objects

3. Code Analysis

4. Design（UML）

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• list

• inheritance

• abstraction

• polymorphism

Keywords example

1a. key: is the value used to access the address in a heap (false) example: HashMap<Key, Value> exampleHashMap; static override int private, final, int, implement, interface, abstract, this, override

1b. (i). lists: ordered / non-ordered.

exampleArrayList.add(Value)
Song.add(songTitle)
exampleHashMap.put(Key, Value)
songTitle.put(1, "Always with Me")

(ii)

for (int i = 0; i < 10; i++) {}
for (Datatype each : Song) (enhanced for loop)

2a.

public class Country() {
    String name;
    int population;
    LocalDate date;
}

HashMap<String, Country> countinents
public Country(String name, int population, LocalDate date) {
    this.name = name;
    date = System.now;
}

Code analysis——Exception

try {
    FileInputStream fileIn = new FileInputStream(filePath);
} catch (FileNotFound)

  catch (IllegalArgumentException)

  catch (IO Exception)

OOD

aggregation 💠菱形表示不确定个数，如大约...个 →箭头表示确定个数

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Collateral Reading

[!TIP] 📖 Java异常处理