如何从Linkedlist类实现一个方法来反转我的linkedList？

Question

如何使用的方法从LinkedList类打印我的链表阵列以相反的顺序：

for (int j = 0; j < FutureValueLinkedList.size(); j++) 
    { 

     String myArrayLinkedList = FutureValueLinkedList.get(j); 
     System.out.println(myArrayLinkedList + "\t"); 
    } 
    System.out.println(); 

将addlast仅（）能够做到这一点？

import java.util.*; 
import java.text.*; 

public class FutureValueApp 
{ 
public static void main(String[] args) 
{ 
    LinkedList<String> FutureValueLinkedList = new LinkedList<>(); 
    // display a welcome message 
    System.out.println("Welcome to the Future Value Calculator"); 
    System.out.println(); 

    // perform 1 or more calculations 
    Scanner sc = new Scanner(System.in); 
    String choice = "y"; 
    while (choice.equalsIgnoreCase("y")) 
    { 

     // get the input from the user 
     System.out.println("DATA ENTRY"); 
     double monthlyInvestment = getDoubleWithinRange(sc, 
      "Enter monthly investment: ", 0, 1000); 
     double interestRate = getDoubleWithinRange(sc, 
      "Enter yearly interest rate: ", 0, 30); 
     int years = getIntWithinRange(sc, 
      "Enter number of years: ", 0, 100); 

     // calculate the future value 
     double monthlyInterestRate = interestRate/12/100; 
     int months = years * 12; 
     double futureValue = calculateFutureValue(
      monthlyInvestment, monthlyInterestRate, months); 

     // get the currency and percent formatters 
     NumberFormat currency = NumberFormat.getCurrencyInstance(); 
     NumberFormat percent = NumberFormat.getPercentInstance(); 
     percent.setMinimumFractionDigits(1); 

     // format the result as a single string 
     String results = 
       "Monthly investment:\t" 
        + currency.format(monthlyInvestment) + "\n" 
      + "Yearly interest rate:\t" 
        + percent.format(interestRate/100) + "\n" 
      + "Number of years:\t" 
        + years + "\n" 
      + "Future value:\t\t" 
        + currency.format(futureValue) + "\n"; 

     // print the results 
     System.out.println(); 
     System.out.println("FORMATTED RESULTS"); 
     System.out.println(results); 

     String monthlyInvestmentFormat = currency.format(monthlyInvestment); 
     String interestRateFormat = percent.format(interestRate/100); 
     String futureValueFormat = currency.format(futureValue); 

     FutureValueLinkedList.add(monthlyInvestmentFormat + "\t" + 
     interestRateFormat + "\t" + Integer.toString(years) + 
       "\t" + futureValueFormat); 




     // see if the user wants to continue 
     System.out.print("Continue? (y/n): "); 
     choice = sc.next(); 
     System.out.println(); 
    } 

    System.out.println("Future Value Calculations "); 
    System.out.println(); 
    System.out.print("Inv/Mo.\tRate\tYears\tFuture Value\n"); 
    for (int j = 0; j < FutureValueLinkedList.size(); j++) 
    { 

     String myArrayLinkedList = FutureValueLinkedList.get(j); 
     System.out.println(myArrayLinkedList + "\t"); 
    } 
    System.out.println(); 
} 

Answer 1

看一看LinkedList#descendingIterator()

LinkedList<Integer> l = new LinkedList<Integer>(); 
l.add(1); 
l.add(2); 
l.add(3); 

Iterator i = l.descendingIterator(); 
while(i.hasNext()) { 
    System.out.print(i.next() + " "); 
} 

打印出：

3 2 1 

Answer 2

如果您只是想输出反转的列表，可以使用descendingIterator作为Ostap的建议。但是，如果要存储反向名单的地方，那么你可以做这样的：

LinkedList<String> reversedFutureValueLinkedList = Collections.reverse(FutureValueLinkedList);