Katherine - private class - 2025 Feb 25

Bank.java

class Bank {
    private int balance;

    public Bank(int initBalance) {
        balance = initBalance;
    }

    public void add(int amt) {
        if (amt <= 0) {
            System.out.println("huh?");
            balance -= 1;
        } else {
            balance += amt;
        }
    }

    public void remove(int amt) {
        if (amt < 0) {
            System.out.println("?");
        } else if (amt > balance) {
            System.out.println("!");
        } else {
            balance -= amt;
        }
    }

    public int getBalance() {
        return balance;
    }

    public static void main(String[] args) {
        Bank b = new Bank(10); // { balance: 10 }
        b.add(10); // {balance: 20}
        b.add(-1); // "huh" 라고 에러나고 -1불 차감 {balance: 19}
        b.remove(20); // error due to insufficient balance
        System.out.println(b.getBalance());
    }
}

Person.java

class Person {
    private int age; // instance var
    private String name;

    // constructor
    public Person(String name, int age) {
        this.age = age;
        this.name = name;
        System.out.println("누가 태어남");
    }

    // setter methods
    public void setAge(int age) {
        this.age = age;
    }

    // getter methods
    public int getAge() {
        return age;
    }

    public String getName() {
        return name;
    }

    // main method can also be in a different class
    public static void main(String[] args) {
        Person p = new Person("James", 10);
        p.setAge(20);
        System.out.println(p.getName() + " is " + p.getAge() + " years old");

    }
}

Team.java

import java.util.ArrayList;

public class test {
    public static void main(String[] args) {
        Team t = new Team(10, 4);
        t.win();
        t.win(2);
        t.lose();
        System.out.println(t.getWinningPercentage());
    }
}

class Team {
    int w;
    int l;

    Team() {
        // 아무 것도 안하는 "empty constructor"
    }

    Team(int w, int l) {
        this.w = w;
        this.l = l;
        // Overloaded constructor
    }

    void win() {
        w += 1;
    }

    void win(int streak) {
        w += streak;
    }

    void lose() {
        l -= 1;
    }

    void lose(int streak) {
        l += streak;
    }

    double getWinningPercentage() {
        double wp = (double) w / (w + l);
        return wp * 100;
    }

}