Nội dung kiến thức:
	- Vòng lặp (for, while, do ... while)
	- Mảng
			- Index -> Giống C/C++
			- Collection -> Mảng động
				- ArrayList
				- Vector
	- OOP:
		T/c bao đóng
=================================================================
OOP:
Quản lý khách sạn:
	- Xác định thực thể (models):
		- Thông tin về ks -> Đối tượng -> Chuyển đổi vào trong ngôn ngữ lập trình -> OOP
		- phong
		- Đồ dùng
		...
Quản lý sinh viên:
	- Thực thể của dự án
		- Sinh viên -> Student
			- Thuộc tính:
				tên -> fullname -> String
				tuổi -> age -> int
				địa chỉ -> address -> String
				email -> String
				...
			- Hành động -> function (hàm) & method (phương thức)
				ăn
				ngủ
				học
				...
			A, 20, Ha Noi, a@gmail.com
		- Kỳ học
		- Môn học
		- Điểm thi
		...

#Main.java

/*
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 */
package com.gokisoft.c2209i.lesson02;

/**
 *
 * @author teacher
 */
public class Main {
    public static void main(String[] args) {
        int x = 1;
        //x = x + 10;
        //x+=10;
        
        //x = x + 1;
        //x += 1; 
        //x++ -> gan trc -> thay doi gia tri sau
        //++x -> thay doi gia tri trc -> sau do moi gan
        
        //x = x - 10;
        //x -= 10;
        
        
        //x = x - 1
        //x -= 1
        //x--
        //--x
        int y = x++; //y = 1, x = 2
        System.out.println("x = " + x + ", y = " + y);
        //x = 2, y = 1 -> 1
        //ko co dap an.
        int z = ++y;
        System.out.println("x = " + x + ", y = " + y + ", z = " + z);
        //x = 2, y = 2, z = 2
        int t = x++ + ++x + y-- - --z + 1;
        //x = 4, y = 1, z = 1, t = 2(x=3) + (x=4)4 + 2(y=1) - (z=1)1 + 1 = 8
        System.out.println("x = " + x + ", y = " + y + ", z = " + z + ", t = " + t);
    }
}

#Student.java

/*
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 */
package com.gokisoft.c2209i.lesson02;

/**
 *
 * @author teacher
 */
public class Student {
    public String fullname;
    public int age;
    public String address;
    public String email;
    
    //TH -> class object -> ko co ham tao -> Tu dong tao ra 1 ham tao ko doi
    public Student() {
        System.out.println("Khoi tao doi tuong");
    }
    
//    public Student(String abc) {
//        System.out.println("Khoi tao doi tuong > " + abc);
//    }
    public Student(String fullname) {
        //Local Var
        this.fullname = fullname;
    }
    
    public Student(String fname, int tuoi) {
        fullname = fname;
        age = tuoi;
    }

    public Student(String fullname, int age, String address, String email) {
        this.fullname = fullname;
        this.age = age;
        this.address = address;
        this.email = email;
    }
    
    public void eating() {
        System.out.println("Eating ...");
    }
    
    public void sleeping() {
        System.out.println("Sleeping ...");
    }
    
    public void learning() {
        System.out.println("Learning ... " + fullname);
    }
}

#Test.java

/*
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 */
package com.gokisoft.c2209i.lesson02;

import java.util.Scanner;

/**
 *
 * @author teacher
 */
public class Test {
    public static void main(String[] args) {
        //Khai bao mang index
        //B1. Khai bao 1 mang 9 so nguyen -> thay int bang: char, boolean, String, float, double
//        int[] t = new int[9];
//        int[] t;
        int t[];
        t = new int[9];
        int k[] = new int[9];
        
        //B2. Gan du lieu vao mang
        //Độ dài mảng index -> length: 9
        //index: 0 -> length - 1 = 8
//        t[10] = 100;
        t[3] = 10;
        System.out.println("t[3] = " + t[3]);
        
        Scanner scan = new Scanner(System.in);
        System.out.println("Nhap t[0] = ");
        t[0] = scan.nextInt();
        System.out.println("t[0] = " + t[0]);
        
        //Su dung loop: for -> de nhap du lieu
        for (int i = 0; i < 9; i++) {
            System.out.println("Nhap t[" + i + "] = ");
            t[i] = scan.nextInt();
        }
        
//        t = new int[20];
        
        System.out.println("Danh sach phan tu: ");
        for (int i = 0; i < 9; i++) {
            System.out.println(t[i] + " ");
        }
        
        //TH -> mang gom cac phan tu san co
        int[] u = {5, 6, 3, 1, 8};
        
    }
}

#Test2.java

/*
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 */
package com.gokisoft.c2209i.lesson02;

import java.util.ArrayList;

/**
 *
 * @author teacher
 */
public class Test2 {
    public static void main(String[] args) {
        //ArrayList -> Thay bang -> Vector
        //B1. Khai bao mang dong -> Kieu du lieu la so int
        //length: t.size(), index: 0 -> length - 1
        ArrayList<Integer> t = new ArrayList<>();
        
        //B2. Them phan tu vao mang
        //Them 5 vao mang
        t.add(5);//length: 1, index = 0, {5}
        t.add(8);//length: 2, index = 0 -> 1, {5, 8}
        t.add(10);//length: 3, index = 0 -> 2, {5, 8, 10}
        
        //B3. Lay phan tu trong magn ra
        System.out.println("t[0] = " + t.get(0));
        System.out.println("t[1] = " + t.get(1));
        System.out.println("t[2] = " + t.get(2));
        
        //B4. Chen 1 phan tu vao trong mang
        //chen 100 -> vao vi tri index: 1 -> {5, 100, 8, 10}
        t.add(1, 100); //length: 4, index = 0 -> 3, {5, 100, 8, 10}
        
        //B5. Xoa 1 phan tu trong mang di
        //Xoa phan tu 8 (index = 2) -> {5, 100, 10}
        t.remove(2);//length: 3, index" 0 -> 2, {5, 100, 10}
        
        //B6. Xoa het cac phan tu trong mang
        t.clear();
        t = new ArrayList<>();
        
        //B7. Sua 1 phan tu trong mang
        //sua index = 1 (100) -> 1000
        t.set(1, 1000);//length: 3, index: 0 -> 2, {5, 1000, 10}
    }
}

#Test3.java

/*
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 */
package com.gokisoft.c2209i.lesson02;

/**
 *
 * @author teacher
 */
public class Test3 {
    public static void main(String[] args) {
        Student stdA;
        stdA = new Student(); //Khoi tao ra 1 vung nho cho bien stdA -> Quan ly thong
        stdA.fullname = "A";
        stdA.age = 20;
        stdA.address = "Ha Noi";
        stdA.email = "a@gmail.com";
        
        stdA = new Student(); //Khoi tao ra 1 vung nho cho bien stdA -> Quan ly thong
        
        stdA.learning();
        System.out.println(stdA.fullname);
        
        Student stdB;
//        stdB = new Student(); //Khoi tao ra 1 vung nho cho bien stdA -> Quan ly thong
//        stdB.fullname = "B";
//        stdB.age = 23;
        stdB = new Student("B", 23);
        stdB.address = "Ha Noi";
        stdB.email = "b@gmail.com";
        
        System.out.println(stdB.fullname);
        stdB.learning();
        
        Student std = new Student("Xin Chao ABC");
        
        
    }
}