import javaioBufferedReader;
import javaioIOException;
import javaioInputStreamReader;
public class TestString {
public static void main(String arg[]) throws IOException {
int a,n;
Systemoutprintln("请输入a,n：");
BufferedReader buf=new BufferedReader(new InputStreamReader(Systemin));
String readStr=bufreadLine();
String argStr[]=readStrsplit(",");
a=IntegerparseInt(argStr[0]);
n=IntegerparseInt(argStr[1]);
long sum=0,aaa=0;
for (int i=1;i<=n;i++){
aaa=(long)getaaa(a,i);
sum+=aaa;
Systemoutprint(aaa);
if (i==n) Systemoutprint("=");
else Systemoutprint("+");
}
Systemoutprintln(""+sum);
}
static double getaaa(int a,int n){
double aaa=a;
for(double i=1;i<n;i++){
aaa+=aMathpow(10, i);
}
return aaa;
}
}
需要注意的是这里面引入了几个java包。
第2个：http://zhidaobaiducom/question/198168341html&__bd_tkn__=6ef56e5d3a2499274a6df875f5b773e682519fb8a07960d151bbad4928e085c42f309a67e9e08f6c24eb7e11a1fbf820dff421b52a
package testbaiduKnowjava实验报告;
//AreaAndLengthjava
class Trangle {
double sideA, sideB, sideC, area, length;
boolean boo;
public Trangle(double a, double b, double c) {
// 代码1 // 参数a,b,c分别赋值给sideA,sideB,sideC
sideA = a;
sideB = b;
sideC = c;
if (a + b > c)
// 代码2) // a,b,c构成三角形的条件表达式
{
// 代码3 // 给boo赋值。}
boo = true;
} else {
// 代码4 // 给boo赋值。}
boo = false;
}
}
double getLength() {
/
代码5 方法体，要求进行判断，如果能构成三角形，则计算出length的值并返回
如果不能构成三角形，则提示“不是一个三角形，不能计算周长”
/
if (boo == true) {
length = sideA + sideB + sideC;
} else {
length = 0;
Systemoutprintln("不是一个三角形，不能计算周长");
}
return length;
}
public double getArea() {
if (boo) {
double p = (sideA + sideB + sideC) / 20;
area = Mathsqrt(p (p - sideA) (p - sideB) (p - sideC));
return area;
} else {
Systemoutprintln("不是一个三角形,不能计算面积");
return 0;
}
}
public void setABC(double a, double b, double c) {
// 代码6 // 参数a,b,c分别赋值给sideA,sideB,sideC
sideA = a;
sideB = b;
sideC = c;
if (a + b > c)
// 代码2) // a,b,c构成三角形的条件表达式
{
// 代码3 // 给boo赋值。}
boo = true;
} else {
// 代码4 // 给boo赋值。}
boo = false;
}
}
}
class Lader {
double above, bottom, height, area;
Lader(double a, double b, double h) {
// 代码10 // 方法体，将参数a,b,c分别赋值给above,bottom,height
above = a;
bottom = b;
height = h;
}
double getArea() {
// 代码11 // 方法体，,要求计算出area返回
area = 05 (above + bottom) height;
return area;
}
}
class Circle {
double radius, area;
Circle(double r) {
// 代码12 // 方法体
radius = r;
}
double getArea() {
// 代码13 // 方法体，要求计算出area返回
return MathPI radius radius;
}
double getLength() {
// 代码14 // getArea方法体的代码,要求计算出length返回
return 2 MathPI radius;
}
void setRadius(double newRadius) {
radius = newRadius;
}
double getRadius() {
return radius;
}
}
public class AreaAndLength {
public static void main(String args[]) {
double length, area;
Circle circle = null;
Trangle trangle;
Lader lader;
circle = new Circle(1);
trangle = new Trangle(3, 4, 5);
lader = new Lader(4, 5, 3);
// 代码15 // 创建对象circle
// 代码16 // 创建对象trangle。
// 代码17 // 创建对象lader
// 代码18 // circle调用方法返回周长并赋值给length
length = circlegetLength();
Systemoutprintln("圆的周长:" + length);
// 代码19 // circle调用方法返回面积并赋值给area
area = circlegetArea();
Systemoutprintln("圆的面积:" + area);
// 代码20 // trangle调用方法返回周长并赋值给length
length = tranglegetLength();
Systemoutprintln("三角形的周长:" + length);
// 代码21 // trangle调用方法返回面积并赋值给area
area = tranglegetArea();
Systemoutprintln("三角形的面积:" + area);
// 代码22 // lader调用方法返回面积并赋值给area
area = ladergetArea();
Systemoutprintln("梯形的面积:" + area);
// 代码23 // trangle调用方法设置三个边，要求将三个边修改为12,34,1。
// 代码24 // trangle调用方法返回面积并赋值给area
area = tranglegetArea();
Systemoutprintln("三角形的面积:" + area);
// 代码25 // trangle调用方法返回周长并赋值给length
area = tranglegetLength();
Systemoutprintln("三角形的周长:" + length);
}
}
public interface Auth {
public void check(String name,String pwd,AuthResult result);
}
class AuthResult{
public String msg;// 结果信息
public boolean success;// 验证结果
public boolean isSuccess(){
return success;
}
public String getMsg(){
return msg;
}
}
import javaioBufferedReader;
import javaioInputStream;
import javaioInputStreamReader;
import javautilHashMap;
import javautilMap;
public class Auth1 implements Auth {
Map<String, String> data = new HashMap<String, String>();
@Override
public void check(String name,String pwd,AuthResult result) {
try {
// 加载用户名和密码
InputStream in = getClass()getResourceAsStream("Auth1txt");
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String temp = null;
while((temp = brreadLine()) != null){
dataput(tempsplit(":")[0], tempsplit(":")[1]);
}
if(dataget(name) == null){
resultsuccess = false;
resultmsg = "用户名错误";
return;
}
if(!pwdequals(dataget(name))){
resultsuccess = false;
resultmsg = "密码错误";
return;
}
resultsuccess = true;
resultmsg = "auth success!";
} catch (Exception e) {
eprintStackTrace();
}
}
}
public class Auth2 implements Auth {
Map<String, String> data = new HashMap<String, String>();
@Override
public void check(String name,String pwd,AuthResult result) {
try {
// 加载用户名和密码
InputStream in = getClass()getResourceAsStream("Auth2txt");
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String temp = null;
int i = 1;
String temp1 = null;
while((temp = brreadLine()) != null){
if(i % 2 == 0){
dataput(temp1, temp);
} else {
temp1 = temp;
}
i++;
}
if(dataget(name) == null){
resultsuccess = false;
resultmsg = "用户名错误";
return;
}
if(!pwdequals(dataget(name))){
resultsuccess = false;
resultmsg = "密码错误";
return;
}
resultsuccess = true;
resultmsg = "auth success!";
} catch (Exception e) {
eprintStackTrace();
}
}
}
import javautilScanner;
public class Test {
public static void main(String[] args) {
Auth1 a1 = new Auth1();
Auth2 a2 = new Auth2();
Scanner sc = new Scanner(Systemin);
String name = null;
String pwd = null;
Systemoutprintln("enter name:");
name = scnextLine();
Systemoutprintln("enter pwd:");
pwd = scnextLine();
AuthResult result = new AuthResult();
Systemoutprintln("---Auth1---check");
a1check(name,pwd,result);
if(resultisSuccess()){
Systemoutprintln("auth success!");
} else {
Systemoutprintln("auth fail! because " + resultgetMsg());
}
Systemoutprintln("---Auth2---check");
a2check(name,pwd,result = new AuthResult());
if(resultisSuccess()){
Systemoutprintln("auth success!");
} else {
Systemoutprintln("auth fail! because " + resultgetMsg());
}
}
}
文件与这些类同包下应该就能读到
Auth1txt
name1:pwd1
name2:pwd2
Auth2txt
name3
pwd3
name4
pwd4
public class Vehicle {
private int speed;
private String brand;
private String no;
public Vehicle() {
}
public Vehicle(int speed, String brand, String no) {
thisspeed = speed;
thisbrand = brand;
thisno = no;
}
public int getSpeed() {
return speed;
}
public void setSpeed(int speed) {
thisspeed = speed;
}
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
thisbrand = brand;
}
public String getNo() {
return no;
}
public void setNo(String no) {
thisno = no;
}
public String showInfo() {
return "speed:" + speed + ",brand=" + brand + ",no=" + no;
}
public static void main(String[] args) {
Vehicle v1 = new Vehicle(150, "brand1", "123");
Vehicle v2 = new Vehicle(100, "brand2", "976");
Vehicle v3 = new Vehicle(200, "brand3", "231");
int averSpeed = (v1speed + v2speed + v3speed) / 3;
Systemoutprintln("三辆车的平均速度为：" + averSpeed);
}
}
1。Peoplejava
public class People {
//性别（sex）及出生日期（date）；方法成员有：获取人的性别和出生日期及构造方法。要求构造方法可以设置性别和出生日期的初始值。
private int sex;
private Date birth;
public People (int sex, Date birth) {
thissex = sex;
thisbirth = birth;
}
public int getSex() {
return thissex;
}
public Date getBirth() {
return thisbirth;
}
}
2。Studentjava
public class Student extends People{
private int sex;
private Date birth;
private String name;
private int stuno;
private double grate;
private String studentNative;
public Student(int sex, Date birth, String name, int stuno, double grate, String studentNative) {
super(sex, birth);
thisname = name;
thisstuno = stuno;
thisgrate = grate;
thisstudentNative = studentNative;
}
public Date getBirth() {
return birth;
}
public double getGrate() {
return grate;
}
public String getName() {
return name;
}
public int getSex() {
return sex;
}
public String getStudentNative() {
return studentNative;
}
public int getStuno() {
return stuno;
}
}
3。测试类自己编写就好了，创建一个People和Student的对象，然后设置值，取值就可以了。
五。
1构造方法没有返回值，方法名和类名一样
2继承是指子类可以拥有父类的方法和属性；多态是指父类的引用可以指向子类对象的实例
3重写
4重载
欢迎分享，转载请注明来源：表白网
微信扫一扫
支付宝扫一扫
评论列表（0条）