Java(面向对象)
面向对象编程的本质:
-
以类的方式组织代码,以对象的组织(封装)数据。
示例:非静态方法调用类(不加static)
public class Demo01 {
public static void main(String[] args){
//对象类型 对象名 = 对象值;
Student student = new Student();
student.say();
}
}
定义一个学生类:
public class Student {
//非静态方法
public void say(){
System.out.println("hello word!");
}
}
示例:静态方法调用类(加static)
public class Demo01 {
public static void main(String[] args) {
Student.say();
}
}
定义一个学生类:
public class Student {
//静态方法
public static void say(){
System.out.println("hello word!");
}
}
Java(封装)
private(私有)
1. 提高程序的安全性,保护数据
2. 隐藏代码的实现细节
3. 统一接口
4. 系统可维护性增加了
用get()输出和set()赋值
示例:
public class Demo02 {
public static void main(String[] args) {
Student xiaoming = new Student();
xiaoming.setName("小明");
xiaoming.setAge(10);
System.out.println(xiaoming.getName());
System.out.println(xiaoming.getAge());
Student xiaohong = new Student();
xiaohong.setName("小红");
xiaohong.setAge(11);
System.out.println(xiaohong.getName());
System.out.println(xiaohong.getAge());
}
}
public class Student {
private String name;
private int age;
public String getName(){
return this.name;
}
public void setName(String name){
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}