*4.26（金融應用：貨幣單位）重寫程序清單2-10，解決將float型值轉換為int型值時可能會造成精度損失的問題。讀取的輸入值是一個字符串，比如"11.56"

• 題目
• • 題目概述
  • 程序清單2-10
  • 破題
• 代碼

題目

題目概述

*4.26（金融應用：貨幣單位）重寫程序清單2-10，解決將float型值轉換為int型值時可能會造成精度損失的問題。讀取的輸入值是一個字符串，比如"11.56"
你的程序應該應用indexOf和substring方法提取小數點前的美元數量，以及小數點后的美分數量

程序清單2-10

import java.util.Scanner;public class QingDan {public static void main(String[] args) {// Create a ScannerScanner input = new Scanner(System.in);// Receive the amountSystem.out.println("Enter an amount in int, for example 11.56");double amount = input.nextDouble();int remainingAmount = (int)(amount * 100);// Find the number of one dollarsint numberOfOneDollars = remainingAmount / 100;remainingAmount = remainingAmount % 100;// Find the number of quarters in the remaining amountint numberOfQuarters = remainingAmount / 25;remainingAmount = remainingAmount % 25;// Find the number of dimes in the remaining amountint numberOfDimes = remainingAmount / 10;remainingAmount = remainingAmount % 10;// Find the number of nickels in the remaining amountint numberOfNickels = remainingAmount / 5;remainingAmount = remainingAmount % 5;// Find the number of pennies in the remaining amountint numberOfPennies = remainingAmount;// Display resultsSystem.out.println("Your amount" + remainingAmount + " consists of");System.out.println(" " + numberOfOneDollars + " dollars");System.out.println(" " + numberOfQuarters + " quarters");System.out.println(" " + numberOfDimes+ " dimes");System.out.println(" " + numberOfNickels + " nickels");System.out.println(" " + numberOfPennies+ " pennies");} }

破題

主要在Scanner句子（獲取用戶輸入數據）后，到開始對輸入的數據進行轉換前這一部分需要修改

接收：更改為String類型接收

通過indexOf()獲取小數點的位置

substring()截取小數點前、小數點后數字部分

轉化為int類型，每位數字*100

代碼

import java.util.Scanner;public class Test4_26 {public static void main(String[] args) {// Create a ScannerScanner input = new Scanner(System.in);// Receive the amountSystem.out.println("Enter an amount in float, for example 11.56");String str = input.next();// 通過indexOf()獲取小數點的位置（下標）int point = str.indexOf(".");// 截取小數點前后數字String st1 = str.substring(0, point);String st2 = str.substring(point+1);// 轉化為int類型，每位數字*100int num1 = Integer.parseInt(st1) * 100;int num2 = Integer.parseInt(st2);if(st2.length() == 1){num2 *= 10;}int remainingAmount = num1 + num2;// Find the number of one dollarsint numberOfOneDollars = remainingAmount / 100;remainingAmount = remainingAmount % 100;// Find the number of quarters in the remaining amountint numberOfQuarters = remainingAmount / 25;remainingAmount = remainingAmount % 25;// Find the number of dimes in the remaining amountint numberOfDimes = remainingAmount / 10;remainingAmount = remainingAmount % 10;// Find the number of nickels in the remaining amountint numberOfNickels = remainingAmount / 5;remainingAmount = remainingAmount % 5;// Find the number of pennies in the remaining amountint numberOfPennies = remainingAmount;// Display resultsSystem.out.println("Your amount" + remainingAmount + " consists of");System.out.println(" " + numberOfOneDollars + " dollars");System.out.println(" " + numberOfQuarters + " quarters");System.out.println(" " + numberOfDimes+ " dimes");System.out.println(" " + numberOfNickels + " nickels");System.out.println(" " + numberOfPennies+ " pennies");} }

總結

以上是生活随笔為你收集整理的Java黑皮书课后题第4章：*4.26（金融应用：货币单位）重写程序清单2-10，解决将float型值转换为int型值时可能会造成精度损失的问题。读取的输入值是一个字符串，比如“11.56“的全部內容，希望文章能夠幫你解決所遇到的問題。

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