Java StringBuffer codePointBefore()方法

java.lang.StringBuffer.codePointBefore() 法指定索引之前，返回字符(Unicode代码点)。该索引(Unicode代码单元)范围是1到length()的 char值。

1 语法

public int codePointBefore(int index)

2 参数

index ： 这是应返回代码点的索引。

3 返回值

此方法返回给定索引之前的Unicode代码点值。

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * Java StringBuffer codePointBefore()方法
 */
import java.lang.*;

public class StringBufferDemo {

  public static void main(String[] args) {
  
    StringBuffer buff = new StringBuffer("TUTORIALS");
    System.out.println("buffer = " + buff);

    // returns the codepoint before index 3
    int retval = buff.codePointBefore(3);
    System.out.println("Character(unicode point) = " + retval);
    
    buff = new StringBuffer("amrood admin ");
    System.out.println("buffer = " + buff);
    // returns the codepoint before index 6
    retval = buff.codePointBefore(6);
    System.out.println("Character(unicode point) = " + retval);
  }
}

输出结果为：

buffer = TUTORIALS
Character(unicode point) = 84
buffer = amrood admin
Character(unicode point) = 100