Java ListIterator previousIndex()用法及代碼示例

ListIterator 接口的 previousIndex() 方法用於返回給定元素的索引，該索引由對前一個的調用返回。當且僅當迭代器位於列表的開頭時，該方法才可能返回 -1。

用法

int previousIndex()

參數

上麵的方法用於返回給定元素的索引，該索引由對 previous 的調用返回。當且僅當迭代器位於列表的開頭時，該方法才可能返回 -1。

例子1

import java.util.ArrayList;
import java.util.ArrayList;
import java.util.ListIterator;
public class JavaListIteratorpreviousIndexExample1 {
   public static void main(String[] args) {
       ArrayList < Character > characters = new ArrayList < Character > ();
   	characters.add('R');
   	characters.add('E');
   	characters.add('A');
   	characters.add('L');
ListIterator < Character > listIterator = characters.listIterator();
System.out.println("The letters are listed as:"+characters);
       System.out.println("The Previous Index is:" + listIterator.previousIndex());
       listIterator.next();   
       System.out.println("The Previous Index is:" + listIterator.previousIndex());
       listIterator.next();
       System.out.println("The Next Index is:" + listIterator.previousIndex());
       listIterator.next();
       System.out.println("The Next index is:" + listIterator.previousIndex());     
   }
}

輸出：

The letters are listed as:[R, E, A, L]
The Previous Index is:-1
The Previous Index is:0
The Next Index is:1
The Next index is:2

例子2

import java.util.ArrayList;
import java.util.ListIterator;
public class JavaListIteratorpreviousIndexExample2 {
  public static void main(String[] args) {
      ArrayList < Long > number = new ArrayList < Long > ();
          number.add(34l);
          number.add(78l);
          number.add(57l);
    ListIterator < Long > listIterator = number.listIterator();
    System.out.println("The numbers are listed as:"+number);
           System.out.println("The Previous Index is:" + listIterator.previousIndex());
           listIterator.next();   
           System.out.println("The Previous Index is:" + listIterator.previousIndex());
           listIterator.next();
           System.out.println("The Next Index is:" + listIterator.previousIndex());
  }
}

輸出：

The numbers are listed as:[34, 78, 57]
The Previous Index is:-1
The Previous Index is:0
The Next Index is:1

相關用法

注：本文由純淨天空篩選整理自 Java ListIterator previousIndex() Method。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。