public class CoffeeMachine {
    private boolean isOn;// 这里是属性，其他类获取不到这个属性，只有这个类内部可以获取到
    private double coffeeAmount;
    private double temperature;

    //Getter and Setter, 虽然都是方法，但是和方法区分一下，因为他们是用来获取和设置属性的
    public boolean getSth() {
       //here is internal logic, no need to know
    }

    public void setSth(boolean isOn) {
        this.isOn = isOn;
    }


    // Method, function, also operation
    public void preHeat() {

    }
}

public class Machine {
    private boolean isOn;// all machines should have these two attribute，我们从牛奶打泡机和咖啡机的属性中抽象而出来的，也叫 refactor，oop里面的一个重要概念
    private double temperature;

    //general getter, setter, and opertation
    public void generalMethod(){
    //here is internal logic, no need to know
    }

    //....

}

public class CoffeeMachine extends Machine {
    private double coffeeAmount;//不是所有机械都有咖啡量的属性吧，咱专属的属性就不要给别人了，毕竟牛奶打泡机你可没有，那就放这里了吧

    // Additional methods specific to CoffeeMachine
    public void someOperations(){

    }
}

public class MilkFrother extends Machine {
    private double milkAmount;// see coffee machine, they both tell the same story

    public double getMilkAmount() {
        return milkAmount;
    }

    public void setMilkAmount(double milkAmount) {
        this.milkAmount = milkAmount;
    }

    @Override
    public void someOperations(){
       /*
    Override，当子类拥有和父类相同的签名（即 public void someOperations() 完全一样的方法）时，注意参数也要一样，子类可以覆盖父类的方法。
    这种情况存在于我们抽象出父类的共有方法，但某一个子类有特殊的执行方法，那么就可以 override 它。具体内容将在 OOP 节展开，这里只是告诉大家这个概念，
    感兴趣的可以自行寻找资源了解 OOP，因为属于比较重要的程序范式，所以对应资源极其丰富，视频网站排前面的几个应该都还行。
    */
}

    // Additional methods specific to MilkFrother
    public void someOperations(){

    }
}

public void operateMachine(Machine machine) {
    machine.preHeat();
    System.out.println("Machine is now ready.");
}

public static void main(String[] args) {
    CoffeeMachine coffeeMachine = new CoffeeMachine();
    MilkFrother milkFrother = new MilkFrother();

    operateMachine(coffeeMachine);
    operateMachine(milkFrother);
}

class CoffeeMachine:
    def __init__(self):
        self.is_on = False # attribute here, same as java
        self.coffee_amount = 0.0
        self.temperature = 20.0

    def doSth():
      # doSth, operation, same as java,

//java
public class MyFirstProgram{
  public static void main (String[] args){
    System.out.println("HELLO WORLD !")
  }
}

#python
pring("HELLO WORLD !")

def turn_on_machine():
    return "Machine is on"

def set_temperature(temp):
    return f"Temperature set to {temp} degrees"

def brew_coffee():
    return "Brewing coffee"

"""
This is a higher order function, you are passing function to another function,
but imo, JS is better to illustrate hof, because functions are the first class
citizen there. And if you have taken the courese we will give you about higher
order function, you will find this function did not recieve any parameters, but
it you can see it is a higher order function, cause it is seeking the parameters from the
global scope.
这是一个高阶函数，你正在将一个函数传递给另一个函数，但在我看来，JavaScript 更适合用来说明高阶函数，
因为在 JavaScript 中函数是一等公民。如果你参加了我们关于高阶函数的课程，你会发现这个函数没有接收任何参数，
但你可以看到它是一个函数，因为它正在从全局作用域中寻找参数。
你更喜欢在注释里用英文还是中文呢？还是双语呢，在评论区留下你的想法，我们会根据大家的反馈来调整注释的语言。
"""

def make_coffee():
    steps = [turn_on_machine, set_temperature, brew_coffee]
    for step in steps:
        result = step() if step != set_temperature else step(90.0)
        print(result)

make_coffee()

#include <stdio.h>

// function in C
void turnOnMachine() {
    printf("Turning on the coffee machine...\n");
}

void setTemperature(double temp) {
    printf("Setting temperature to %.1f degrees...\n", temp);
}

void brewCoffee() {
    printf("Brewing coffee...\n");
}

int main() {
    // procedure
    turnOnMachine();
    setTemperature(90.0);
    brewCoffee();
    return 0;
}

-- create a table（DDL）is to give the definition
CREATE TABLE CoffeeOrders (
    id INT PRIMARY KEY AUTO_INCREMENT,
    temperature INT,
    coffee_beans_weight INT,
    water_volume INT,
    status VARCHAR(50)
);

-- Do something（DML）,as you can see, sql are giving you a cup of coffee with 90 degree, 30g coffee beans, 200ml water
INSERT INTO CoffeeOrders (temperature, coffee_beans_weight, water_volume, status)
VALUES (90, 30, 200, 'Pending');
SELECT * FROM CoffeeOrders WHERE status = "Pending";