Fuxi内容：①类创对象，②final，static方法的调用，③私有封装，构造器，修改器， ④抽象类，接口
package review;
public class Fuxi {//内容：①类创对象，②final，static方法的调用，③私有封装，构造器，修改器， ④抽象类，接口
public static void main(String[] args) {
//Function test = new Function();
Fuxi.test1();//法二调用测试！
}
public static void test1() {
int a[] = {1,2,3,4,5};
Function.reserve(a);
Function.printarray(a);//静态方法的两种调用，多了个类名.调用
Function f = new Function();
f.printarray(a);//静态方法的两种调用
System.out.println(f.Chinese);
Function f1 = new Function("个一百",1);
f1.setMoney(6);
System.out.println(f1.money + f1.getName() );
}
}
//接口多继承性
class Function extends a implements b ,c{ //abstract class Function implements b就可以不实现抽象方法但不能造对象了，接口不能定义构造器，也不能创对象；
static final String Chinese = "中国人" ;
private String name;
int money;
public Function() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getMoney() {
return money;
}
public void setMoney(int money) {
this.money = money;
}
public Function(String name,int money) {
this.money = money;
this.name = name;
//name = "zg"; 局部变量赋值罢了
}
public static void reserve(int a[]){ //不加返回值变构造器，没有静态构造器
for(int i = 0;i < a.length/2;i++) {//i < a.length两次换
int temp = a[i];
a[i] = a[a.length - 1 - i];
a[a.length - 1 - i] = temp;
}
return ;
}
static void printarray(int a[]) { //静态方法类名调用，或创建对象
for(int i = 0;i < a.length;i++) {
System.out.print(a[i] +" ");
}
System.out.println();
}
@Override
public void usb() {
// TODO Auto-generated method stub
}
@Override
public void bb() {
// TODO Auto-generated method stub
}
}
abstract class a{
a(){//可以构造器
}
}
interface b{//接口（静态常量、抽象方法，）
public abstract void usb();
void bb();//省略public abstract
//public b(){}; 不能定义构造器，不能创对象， 借用最终子类（非抽象）实现方法，子类对象调用方法
}
interface c{
}
Fuxi2内容：
① equals
②包装类
③toString()打印对象地址值显示,文件.类名@哈希计算值，可重写，Date，String库中就已重写
package review;
public class Fuxi2 {//① equals ---- ②包装类 ---- ③toString()打印对象地址值显示,文件.类名@哈希计算值，可重写，Date，String就已重写
//String的toString是打印字符串
public static void main(String[] args) {//
Circle text = new Circle();
text.test1();
}
}
class Circle{
double radius;
public Circle() {
}
public Circle(double radius) {
this.radius = radius;
}
public void test1() {
Circle c1 = new Circle(1.1);
Circle c2 = new Circle(1.1);
System.out.println(c1.equals(c2));
int t = 1;
char ch1 = 'a';
Character c = ch1;
Integer n = t;//自动装箱 转换包装类 做 如Obeject类的类型参数
int m = n;//自动拆箱 //Character , Integer ,其他为大写如Boolean , Float //此处未与String转换
String s = "123";//除了Boolean ，要纯粹"123"转Int 或 abc ( "123a"会throw NumberFormatException )
boolean a = Boolean.parseBoolean(s); //字符串转基本数据类型 （ 包装类.parse包装类() ）
int sint = Integer.parseInt(s);
boolean b =new Boolean("true");
boolean b1 =new Boolean(true);
boolean b2 =new Boolean("true123"); //基本数据类型转字符串
Fuxi2 ff = new Fuxi2();
System.out.println( ff.toString() );
System.out.println(String.valueOf(t));//基本数据类型转字符串 调用String重载的valueOf()
String ssString = t + ""; //基本数据类型转字符串 运算连接
//throw NumberFormatException
//int b = Integer.parseInt(s);
//法二
Boolean B = b;//自动装箱
System.out.println( a );
System.out.println(sint );
System.out.println( b + " " + b1 +b2);
}
@Override
public boolean equals(Object obj) { //比较内容
if (this == obj)
return true;
if(obj instanceof Circle) {
Circle other = (Circle) obj;
return true;
}
return false;
}
}
十六进制 转换 十进制
package review;
import java.lang.System;
public class a1 {
public static void main(String[] args) {
}
}
class huona{
public static int hx(String hex) {
int devalue = 0;
for(int i = 0;i < hex.length();i++) {
char hexchar = hex.charAt(i);
devalue = devalue*16 + hxchar(hexchar);
}
return devalue;
}
public static int hxchar(char ch) {
if(ch>='A' &&ch <= 'F') {
return (ch-'A'+ 10);
}else return (ch-'0');//(int)ch
}
}
数组
package review;
import java.util.Scanner;
public class b1 {
public static void main(String[] args) {
double a = 1;
double []arr[] = {{1,2,3},{1,2,3,4},{1,3,5,7,9}};
double []arr2[] = new double[10][];//行必写，可省略列
double []arr3[] = new double[][]{{1},{2},{3},{2,3}};//写法三
double []arr4 = new double[5];
System.out.println( arr3[0][0]);
}
}
class Cylinder{
private double r = Math.PI;
private double h = 1;
public double getR() {
return r;
}
public void setR(double r) {
this.r = r;
}
public double getH() {
return h;
}
public void setH(double h) {
this.h = h;
}
}
VowelQuestion
package review;
import java.util.Scanner;
public class VowelQuestion {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input= new Scanner(System.in);
String word=input.next();
System.out.println(getFirstVowel(word));
}
public static char getFirstVowel(String word) {
char ch;
for(int i=0;i
大作业
package xuexitong;
public class bigwork {
public static void main(String[] args){
Cylinder C1 = new Cylinder(1,1);
Cylinder C2 = new Cylinder(1,1);
C2.setRadius(6);
System.out.println(C1.equals(C2));
}
}
abstract class Shape {
abstract double getArea();
}
class Circle extends Shape{
double radius;
public Circle() {}
public Circle(double radius) {
this.radius = radius;
}
public double getRadius() {
return radius;
}
public void setRadius(double radius) {
this.radius = radius;
}
@Override
public double getArea() {
return Math.PI*radius*radius;
}
}
class Cylinder extends Circle{
double height;
public Cylinder() {}
public Cylinder(double radius,double height) {
this.height = height;
this.radius = radius;
}
public double getHeight() {
return height;
}
public void setHeight(double height) {
this.height = height;
}
@Override
public double getArea() {
return 2*Math.PI*radius+2*radius*Math.PI*height;
}
@Override
public boolean equals(Object object){//重写比较内容
if(this == object) {
return true;
}
if (object instanceof Circle){//判断obj是否是Circle的实例对象,是就可以向下转型
Circle circle=(Circle)object;
return this.radius==circle.radius;
}
else return false;
}
}
大作业测试
package xuexitong;
public class testbigwork {
public static void main(String[] args) {
Shape[] shape={new Circle(2.3),new Cylinder(3.6,5.8)};
for(Shape object:shape){
System.out.println(object.getArea());
}
}
}
结构体类型数组
package xuexitong;
public class testUsb {
public static void main(String[] args){
Usb []usb={new UsbMouse(),new UsbKeyborder()};
for(Usb object:usb){
object.work();
}
}
}
加密
package xuexitong;
import java.util.Scanner;
public class teacheradvicejiami {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String s = input.nextLine();
password(s);
passwordflagmod(s);
}
public static void password(String s) { //不用数组 ，用String字符串类型和charAt(i)逐个搜索
//A的加密： A = (char)((flag(A) + 3)%26)
for(int n = 0 ;n
