建议先看一下此节,尽量理解一下类,对象,属性和方法.继续接下去看后面的一到两章,尽管会稍微有点模糊,混乱.但是你就知道所谓的类,对象.等的作用.(主要是利用概念来格式化大量知识,便于描述和区分).再来重新看一下此节,那时候就清楚多了,再继续详细看后面的章节,就好学多了........
2016-11-13
public class Test {
public static void main(String[] args) {
Rectangle r = new Rectangle();
r.Input(2, 4);
r.girth();
r.area();
Circle c = new Circle();
c.Input(3);
c.girth();
c.area();
}
}
public static void main(String[] args) {
Rectangle r = new Rectangle();
r.Input(2, 4);
r.girth();
r.area();
Circle c = new Circle();
c.Input(3);
c.girth();
c.area();
}
}
2016-11-12
public class Circle extends Shape{
private double r;
final double PI = 3.14;
public void Input(double r){
this.r = r;
}
public void girth() {
System.out.println("该圆形的周长为:"+ (2*PI*r));
}
public void area() {
System.out.println("该圆形的面积为:"+ (PI*r*r));
}
}
private double r;
final double PI = 3.14;
public void Input(double r){
this.r = r;
}
public void girth() {
System.out.println("该圆形的周长为:"+ (2*PI*r));
}
public void area() {
System.out.println("该圆形的面积为:"+ (PI*r*r));
}
}
2016-11-12
public class Rectangle extends Shape{
private int x;
private int y;
public void Input(int x, int y){
this.x = x;
this.y = y;
}
public void girth() {
System.out.println("该矩形的周长为:"+ (x+y)*2);
}
public void area() {
System.out.println("该矩形的面积为:"+ (x*y));
}
}
private int x;
private int y;
public void Input(int x, int y){
this.x = x;
this.y = y;
}
public void girth() {
System.out.println("该矩形的周长为:"+ (x+y)*2);
}
public void area() {
System.out.println("该矩形的面积为:"+ (x*y));
}
}
2016-11-12
public class HelloWorld {
static int score1 = 86;
static int score2 = 92;
public static int sum(int score1,int score2) {
int m= score1+score2;
return m; }
public static void main(String[] args) {
int allScore =sum(86,92) ;
System.out.println("总分:" + allScore);
}
}
static int score1 = 86;
static int score2 = 92;
public static int sum(int score1,int score2) {
int m= score1+score2;
return m; }
public static void main(String[] args) {
int allScore =sum(86,92) ;
System.out.println("总分:" + allScore);
}
}
2016-11-12
// 创建方法内部类的对象
MInner mi = new MInner();
// 调用内部类的方法
int newScore=mi.getScore();
// 创建外部类的对象
HelloWorld mo = new HelloWorld();
MInner mi = new MInner();
// 调用内部类的方法
int newScore=mi.getScore();
// 创建外部类的对象
HelloWorld mo = new HelloWorld();
2016-11-11