Java学习第二篇:类，对象，成员属性，成员方法，构造方法，类变量，类方法

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

一.类的定义

一个全面的类定义是比较复杂的, 定义如下：

aaarticlea/jpeg;base64,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" alt="" />

二.类的对象

1.如何创建对象

类名对象名=new 类名();

2.如何访问类的成员属性?

对象名.属性名

3.一个简单的程序实例

public class Demo1 {
public static void main(String[] args) {
//创建Cat的一个对象
Cat cat1=new Cat();
cat1.age=3;
cat1.name="xiaohua";
//创建Cat的第二个对象
Cat cat2;
//将cat1赋值给cat2
cat2=cat1;
System.out.println(cat2.age+" "+cat2.name);
}
}class Cat {
int age;
String name;
}

运行结果：

3 xiaohua

三.类的成员方法

1.类的成员方法的定义

aaarticlea/jpeg;base64,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" alt="" />

2.一个简单的程序实例

public class Demo2 {
public static void main(String[] args) {
Calculator calculator=new Calculator();
calculator.calculate(100);
System.out.println(calculator.add(100, 100));
}
}class Calculator{
//成员方法
public void calculate(int n){
System.out.println(n*(n+1)/2);
}
public int add(int n1,int n2){
return n1+n2;
}
}

运行结果：

5050
200

四.类的构造方法

1.构造方法的特点

(1).构造方法名和类名相同;

(2).构造方法没有返回值;

(3).主要作用是完成对新对象的初始化;

(4).在创建对象时,系统自动调用该类的构造方法;

(5).一个类可以有多个构造方法;

(6).每个类都有一个默认的构造方法.

2.一个简单的程序实例

public class Demo3 {
public static void main(String[] args) {
Person p1=new Person();
System.out.println("姓名:"+p1.name+"年龄:"+p1.age); Person p2=new Person(10,"xiaoming");
System.out.println("姓名:"+p2.name+"年龄:"+p2.age);
}
}class Person {
int age;
String name;
//空构造方法
public Person(){
}
//有参构造方法
public Person(int a,String n){
age=a;
name=n;
}
}

运行结果：

姓名:null年龄:0
姓名:xiaoming年龄:10

五.类变量与类方法

1.类变量

(1).类变量是与类相关的, 是公共属性;

(2).加上static称为类变量或者静态变量, 否则称为实例变量;

(3).实例变量是属于每个对象个体的属性;

(4).类变量可以通过类名.类变量名或者对象名.类变量名直接访问.

2.类方法

(1).类方法是与类相关的, 是公共的方法;

(2).类方法中不能访问非静态变量;

(3).可以通过类名.类方法名或者对象名.类方法名使用.

3.简单的程序实例

public class Demo4 {
public static void main(String[] args) {
Child child1=new Child(8, "xiaohuang");
child1.joinGame();
Child child2=new Child(10, "xiaoming");
child2.joinGame(); //访问类变量
System.out.println("共有"+child1.total+"个小孩参加游戏");
System.out.println("共有"+child2.total+"个小孩参加游戏");
System.out.println("共有"+Child.total+"个小孩参加游戏");
}
}class Child {
int age;
String name;
//类变量(静态变量)
static int total=0;
public Child(int age,String name) {
this.age=age;
this.name=name;
}
//统计参加游戏的小孩人数
public void joinGame() {
total++;
}
}

运行结果：

共有2个小孩参加游戏
共有2个小孩参加游戏
共有2个小孩参加游戏

public class Demo5 {
static int i=1;
static {
i++;
}
public Demo5() {
i++;
}
public static void main(String[] args) {
System.out.println(i); Demo5 d1=new Demo5();
System.out.println(i); Demo5 d2=new Demo5();
System.out.println(i);
}
}

运行结果：

2
3
4

public class Demo6 {
public static void main(String[] args) {
Stu stu1=new Stu(10,"xiaoming",120);
Stu stu2=new Stu(20,"xiaohuan",320);
System.out.println(Stu.getTotalFee());
}
}class Stu {
int age;
String name;
static int totalFee=0;
public Stu(int age,String name,int fee) {
this.age=age;
this.name=name;
totalFee+=fee;
}
//静态变量用静态方法访问
//静态方法只能访问静态变量
//普通方法可以访问普通的成员变量,也可以访问静态变量
public static int getTotalFee() {
return totalFee;
}
}