Java中的 BreakIterator previous() 方法及示例
Java.text.BreakIterator类的previous()方法用于获取当前边界(通过调用current() 方法检索到的边界)后面的上一个边界的索引。它提供了在 BreakIterator 指向的当前边界之前的边界第一个字符的偏移量。
句法:
public abstract int previous()
参数:此方法不接受任何参数。
返回值:此方法提供当前边界之后的前一个边界的索引。
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 with zero
int current = 0, next = 0;
// creating and initializing BreakIterator
BreakIterator wb
= BreakIterator.getWordInstance();
// setting text for BreakIterator
wb.setText("Code Geeks");
// setting the current position to index 11
// By skipping 3 boundaries
wb.next(3);
// getting the current text boundary
current = wb.current();
// display the result
System.out.println(
"current position before"
+ " calling previous() : "
+ current);
// calling previous() method
next = wb.previous();
// display the result
System.out.println(
"\ncurrent position after"
+ " calling 1st previous() : "
+ next);
// calling previous() method
next = wb.previous();
// display the result
System.out.println(
"\ncurrent position after"
+ " calling 2nd previous() : "
+ next);
}
}
输出:
current position before calling previous() : 11
current position after calling 1st previous() : 6
current position after calling 2nd previous() : 4
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 with zero
int current = 0, next = 0;
// creating and initializing BreakIterator
BreakIterator wb
= BreakIterator.getWordInstance();
// setting text for BreakIterator
wb.setText("GeeksForGeeks");
// setting the current position to index 11
// By skipping 3 boundaries
wb.next(3);
// getting the current text boundary
current = wb.current();
// display the result
System.out.println(
"current position before"
+ " calling previous() : "
+ current);
// calling previous() method
next = wb.previous();
// display the result
System.out.println(
"\ncurrent position after"
+ " calling 1st previous() : "
+ next);
// calling previous() method
next = wb.previous();
// display the result
System.out.println(
"\ncurrent position after"
+ " calling 2nd previous() : "
+ next);
}
}
输出:
current position before calling previous() : 13
current position after calling 1st previous() : 0
current position after calling 2nd previous() : -1
参考: https://docs.oracle.com/javase/9/docs/api/ Java/text/BreakIterator.html#previous–