Java中的 CollationElementIterator previous() 方法和示例

Java.text.CollationElementIterator 类的previous()方法用于获取前一个Collator 元素。此方法将迭代器推送到前一个元素并返回其值。

句法：

public int previous()

参数：此方法接受任何参数。

返回值：此方法返回前一个整理器元素的值。

以下是说明previous()方法的示例：

示例 1：

// Java program to demonstrate previous() method
  
import java.text.*;
import java.util.*;
import java.io.*;
  
public class GFG {
    public static void main(String[] argv)
    {
        // creating and initializing testString
        String test = "abcd";
  
        // creating and initializing
        // RuleBasedCollator object
        RuleBasedCollator rbc
            = (RuleBasedCollator)(Collator.getInstance());
  
        // creating and initializing
        // CollationElementIterator
        CollationElementIterator cel
            = rbc.getCollationElementIterator(test);
  
        // setting offset to index 4
        cel.setOffset(3);
  
        // display the result
        System.out.println("current offset before"
                           + " calling previous() "
                           + cel.getOffset());
  
        // getting offset of the previous collator element
        // using previous() method
        int value = cel.previous();
  
        // display the result
        System.out.println("\ncurrent element value after"
                           + " calling previous() "
                           + value);
    }
}

输出：

current offset before calling previous() 3

current element value after calling previous() 5505024

示例 2：

// Java program to demonstrate previous() method
  
import java.text.*;
import java.util.*;
import java.io.*;
  
public class GFG {
    public static void main(String[] argv)
    {
        // creating and initializing testString
        String test = "abcd";
  
        // creating and initializing
        // RuleBasedCollator object
        RuleBasedCollator rbc
            = (RuleBasedCollator)(Collator.getInstance());
  
        // creating and initializing
        // CollationElementIterator
        CollationElementIterator cel
            = rbc.getCollationElementIterator(test);
  
        // setting offset to index 2
        cel.setOffset(2);
  
        // display the result
        System.out.println("current offset before"
                           + " calling previous() "
                           + cel.getOffset());
  
        // getting offset of the previous collator element
        // using previous() method
        int value = cel.previous();
  
        // display the result
        System.out.println("\ncurrent offset after"
                           + " calling previous() "
                           + cel.getOffset());
    }
}

输出：

current offset before calling previous() 2

current offset after calling previous() 1

参考： https://docs.oracle.com/javase/9/docs/api/ Java/text/CollationElementIterator.html#next–