1. 在IDE中輸入以下代碼，觀察運行結果，並說明該段程序的作用。
import java.util.Scanner;
public class DisplayTime {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter an integer for seconds: ");
int seconds = input.nextInt();
int minutes = seconds / 60;
int remainingSeconds = seconds % 60;
System.out.println(seconds + " seconds is " + minutes +
" minutes and "+ remainingSeconds + " seconds");
}
}
2. 在IDE中輸入以下代碼，觀察運行結果，並說明該段程序的作用。
import javax.swing.JOptionPane;
public class ComputeLoanUsingInputDialog {
public static void main(String[] args){
//Enter yearly interest rate
String annualInterestRateString = JOptionPane.showInputDialog(
"Enter yearly interest rate,for example 8.25: ");
//Covert string to double
double annualInterestRate =
Double.parseDouble(annualInterestRateString);
//Obtain monthly interest rate
double monthlyInterestRate = annualInterestRate / 1200;
//Enter number of years
String numberOfYearString = JOptionPane.showInputDialog(
"Enter numbers of years as an integer, \nfor example 5: ");
//Convert string to int
int numberOfYears = Integer.parseInt(numberOfYearString);
//Enter loan amount
String loanString = JOptionPane.showInputDialog(
"Enter loan amount,for example 120000.95:");
//Convert String to double
double loanAmount = Double.parseDouble(loanString);
//Calclate payment
double monthlyPayment = loanAmount * monthlyInterestRate / (1
- 1/ Math.pow(1 + monthlyInterestRate, numberOfYears * 12));
double totalPayment = monthlyPayment * numberOfYears *12;
//Format to keep two digits after the decimal point
monthlyPayment = (int)(monthlyPayment * 100) / 100.0;
totalPayment =(int)(totalPayment * 100) / 100.0;
//Display results
String output = "The monthly payment is " + monthlyPayment +
"\nThe total payment is " + totalPayment;
JOptionPane.showMessageDialog(null,output);
}
}
3. 編寫程序：
讀取一個在0-99999之間的整數，將該整數的各位數字相加，如求和結果大於9，則繼續對所獲得的結果數字按各位相加求和，直至求出的和值小於10。
4. 編寫程序：
給定一個10位的整數組成的串，形式如： 。
其中最後的一位（即 ）是校驗和，其使用以下運算規則以前面的9位上的整數作爲參數獲得結果，運算規則爲：
，特別來說，如果校驗和值爲10，則將校驗位的取值寫爲X。
根據如上需求，編寫程序，提示用戶輸入前9個數，然後計算得出第10位校驗和，顯示輸出經過校驗且校驗合格的完整整數串。
5. 編寫程序：
對輸入的字符串進行反轉並顯示結果，例如輸入字符串爲hello cust，則程序應輸出tsuc olleh，不允許使用已封裝的JDK方法進行處理。
1、
package org.cust.test2;
import java.util.Scanner;
public class DisplayTime {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter an integer for seconds: ");
int seconds = input.nextInt();
int minutes = seconds / 60;
int remainingSeconds = seconds % 60;
System.out.println(seconds + " seconds is " + minutes +
" minutes and "+ remainingSeconds + " seconds");
}
}
//把輸入的秒數轉換爲多少分多少秒的形式
2、
package org.cust.test2;
import javax.swing.JOptionPane;
public class ComputeLoanUsingInputDialog {
public static void main(String[] args){
//Enter yearly interest rate
String annualInterestRateString = JOptionPane.showInputDialog(
"Enter yearly interest rate,for example 8.25: ");
//Covert string to double
double annualInterestRate =
Double.parseDouble(annualInterestRateString);
//Obtain monthly interest rate
double monthlyInterestRate = annualInterestRate / 1200;
//Enter number of years
String numberOfYearString = JOptionPane.showInputDialog(
"Enter numbers of years as an integer, \nfor example 5: ");
//Convert string to int
int numberOfYears = Integer.parseInt(numberOfYearString);
//Enter loan amount
String loanString = JOptionPane.showInputDialog(
"Enter loan amount,for example 120000.95:");
//Convert String to double
double loanAmount = Double.parseDouble(loanString);
//Calclate payment
double monthlyPayment = loanAmount * monthlyInterestRate / (1
- 1/ Math.pow(1 + monthlyInterestRate, numberOfYears * 12));
double totalPayment = monthlyPayment * numberOfYears *12;
//Format to keep two digits after the decimal point
monthlyPayment = (int)(monthlyPayment * 100) / 100.0;
totalPayment =(int)(totalPayment * 100) / 100.0;
//Display results
String output = "The monthly payment is " + monthlyPayment +
"\nThe total payment is " + totalPayment;
JOptionPane.showMessageDialog(null,output);
}
//輸入要借的本金、利率、借多少年 最後輸出每個月還多少以及總額
}
3、
package org.cust.test2;
import java.util.Random;
import java.util.Scanner;
public class Test_1 {
int result;
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
Test_1 t = new Test_1();
int rNumber = 0, nChoice = 0;
String choice, number;
boolean flag = true, sFlag = true;
while (flag) {
System.out.println("請輸入選擇：" + "\n1、自動生成1-99999的數字\n2、手動輸入1-99999的數字");
choice = in.next();
try {
nChoice = Integer.parseInt(choice);
} catch (NumberFormatException e) {
System.out.println("輸入有誤請重新輸入：");
continue;
}
if (nChoice == 1) {
Random rand = new Random();
rNumber = rand.nextInt(100000);
System.out.println("所取的隨機數爲：" + rNumber);
flag = false;
} else if (nChoice == 2) {
while (sFlag) {
System.out.println("請在下面手動輸入數字");
number = in.next();
try {
rNumber = Integer.parseInt(number);
if (rNumber > 99999 || rNumber < 1) {
System.out.println("輸入範圍有誤");
continue;
} else {
sFlag = false;
}
}
catch (NumberFormatException e) {
System.out.println("輸入有誤請重新輸入:");
continue;
}
flag = false;
}
} else {
System.out.println("輸入數字範圍有誤，請重新輸入");
continue;
}
}
t.getR(rNumber, t);
System.out.println("處理結果爲:" + t.result);
}
public void getR(int r, Test_1 t) {
int result = 0;
int a[] = new int[6];
int i = 0;
do {
a[i] = r % 10;
r = r / 10;
i++;
if (r < 10) {
a[i] = r;
i++;
}
} while (r / 10 != 0);
for (int j = 0; j < a.length; j++) {
result += a[j];
}
if (result < 10) {
t.result = result;
} else {
t.getR(result, t);
}
}
}
4、
package org.cust.test2;
import java.util.Scanner;
public class Test_2 {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int nArray[] = new int[9];
String sArray[] = new String[9];
while (true) {
System.out.println("請選擇輸入前9位數的方式：1、依次輸入 2、一次輸入");
int i = in.nextInt();
if (i == 1) {
for (int j = 0; j < nArray.length; j++) {
System.out.print("第" + (j + 1) + "位數：");
nArray[j] = in.nextInt();
}
String r = getResult(nArray);
System.out.println("完整整數串爲：");
for (int q = 0; i < nArray.length; i++) {
System.out.print(nArray[i]);
}
System.out.print(r);
System.out.println("");
} else if (i == 2) {
do {
sArray = enter();
} while (sArray == null);
for (int y = 0; y < sArray.length; y++) {
nArray[y] = Integer.parseInt(sArray[y]);
}
String r = getResult(nArray);
System.out.println("完整整數串爲：");
for (int p = 0; p < nArray.length; p++) {
System.out.print(nArray[p]);
}
System.out.print(r);
System.out.println("");
} else {
System.out.println("選擇有誤，請重新輸入");
}
}
}
public static String[] enter() {
System.out.println("直接輸入如下：");
Scanner in = new Scanner(System.in);
String input = in.nextLine();
String[]eArray=input.split("");
System.out.println(eArray.length);
for(int i=0;i<eArray.length;i++){
System.out.println(eArray[i]);
}
if (eArray.length == 9) {
return eArray;
} else {
System.out.println("輸入整數串長度不爲9，請重新輸入");
return null;
}
}
public static String getResult(int[] iArray) {
String result = null;
int sum = 0;
for (int z = 1; z <= iArray.length; z++) {
sum += iArray[z - 1] * z;
}
sum = sum % 11;
if (sum == 10) {
result = "X";
} else {
result = sum + "";
}
return result;
}
}
5、
package org.cust.test2;
import java.util.Scanner;
public class Test_3 {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String input;
System.out.println("請輸入字符串：");
input = in.nextLine();
System.out.println("反轉後的字符串如下：");
char[] cArray = input.toCharArray();
for (int i = 1; i <= cArray.length; i++) {
System.out.print(cArray[cArray.length - i]);
}
}
}